Sunday, November 29, 2009

Evolution/religion: an Integrative View of Nature, Faith and the Human Mind

Evolution/religion: an Integrative View of Nature, Faith and the Human Mind

November 29th, 2009 by Admin Leave a reply » Evolution/Religion

An Integrative Look at Nature, Faith and the Human Mind

By Robert DePaolo

Freud once described history as a series of race wars, implying that bigotry is and always has been tantamount to a non-malleable virus infecting all of human society

It is a debatable point. Detractors might say mankind can and typically has learned his way out of racial bias as a result of exposure to, interaction with, and dependence on people of other races. For example in recent times the population of blacks and other racial minorities has increased in western nations, providing support in war and industry and enhancing the national spirit in the arts, athletics and literature.

On the other hand, adherents might contend that built into the human genetic code is an equally non-malleable tendency to protect and preserve the local gene pool, and that stranger-hostility is quite characteristic of all primate groups – including homo sapiens.

Some studies seem to support that view, in particular the work of Wilson & Wrangham, (2003). Their results coincide with a main tenet of evolutionary psychology that primitive behaviors devoted to gene pool preservation will take priority over the egalitarian philosophy framing the rules of social interaction in most democratic societies.

In terms of human experience, “strangeness” does not have to be based on race. It can be based on language differences, ethnic background, gender and any number of real and superficial distinctions. It’s just that the physical differences among races makes the process of discriminating between “us” and “them” rather perceptually and emotionally convenient.

Even with distinctive racial traits, “stranger bias” is hardly inevitable. It seems to be merely one of two options provided by the human brain. As Perry, (2008) and Cromwell & Schultz (2003) have suggested, the sheer size of the brain, particularly in the vast regions of the cerebral cortex (a section less influenced by primal urges and more concerned with learning and integrating new associations and concepts) provides a check and balance on our most basal instincts. Indeed Freud’s theory regarding the separation of the ego from the id for impulse control might have its physiological correlate in the frontal cortex.

In that context perhaps, despite Freud, it is not race, but the human capacity to over-distinguish between objects and persons that comprises the true sociopolitical virus. In truth that process, often referred to as discrimination learning, is more of a two sided coin than a virus because when it comes to drawing distinctions, that component of mind can employed for better or for worse; for example to chart the course of history, politics and scientific discovery, leading either to progress or social devolution.

That all good and bad, productive and destructive elements in society emanate from the human mind is a tautology requiring no further elaboration. On the other hand the way in which the human mind works does invite scrutiny, because the mind/brain is a flexible structure by virtue of its genetic and functional make-up, which can lead to any number of behavioral and attitudinal possibilities. In fact, as Mercado (2008) has suggested, the human brain appears to be a kind of bimodal organ constantly shifting between discriminatory and integrative cognitive processes.

Since human brain evolution occurred in the context of an arboreal lifestyle requiring integrative perception, a capacity for figure-ground (stereoscopic) visual distinctions and internal memory to correct for visual and acoustical vagaries in the trees, it tends to bring ideas together into common focus. In that sense the primate brain template provided us with a penchant for integrative thought. On the other hand the latest primate brain revision providing new circuits to facilitate upright walking seems to have led to a bifurcated human mind, featuring a left-right motor cadence requiring separate inhibition-excitation sequences. This process was converted to other functions and led to an enhancement of discrimination and attention capacities. While all creatures can learn to distinguish between stimuli, the finely tuned alternating/competing capacities to separate and integrate experiences appears to play a significant role in th development of both the personality and human culture.

One can see the bimodal mind in action in virtually all human endeavors. For example the ability to put circuit A on hold while circuit B is activated enables the Eskimo not only to walk upright but to describe 12 different kinds of snow. Meanwhile the fact that humans can weave experiences together enables the rest of us to understand that snow consists of one chemically configuration and is simply water at a different state of temperature.

Thus we seem to shift back and forth between convergence and divergence in our actions, thoughts, beliefs and prayers and perhaps the course of human history is partly determined by which of those two trends is emphasized and championed by society at any given time.

It clearly has played a role in American politics. For example the evolution of the political parties has been part real and part illusory – the need for group distinctions often overriding the practicalities of “the party philosophy.” Despite its origin in Jefferson’s democratic-republican party, which favored agriculture over industry and (as evidenced in Jefferson’s letters on moral principles) held to the possibility that agnosticism and morality were not mutually exclusive, the current Republican party has adopted a fairly vigorous religious mindset and champions the cause of industry. Meanwhile Democrats…Dixiecrats, who in earlier times became a collective albatross around the neck of voting rights now claim to be the only party truly sensitive to the plight of minorities. The fact that the members of both parties compete fervently during elections based on ostensibly clear choices in policy and legacy seems to indicate that discriminatory thought for its own sake has prevailed in recent times.

If unnecessary group distinctions have proved to be a mild impediment to the evolution of American society (as accurately predicted by James Madison and Voltaire) such artificial distinctions have been insidious among the so-called major religions.

Depending one what mind-mode is in play, one could assert either that there are no meaningful distinctions among the beliefs of Jews, Christians and Moslems – making several thousand years of hostility seem unnecessary, not to mention foolish, or that the contrasts are so substantial that disputes over territory and doctrine would have been unavoidable in any case.

The integrative part of mind might angle in on the fact that the three faiths have virtually identical moral premises. For example in reading the Bible and the Qur’an one could conclude that the Ten Commandments are a staple of all three religions. While the Christian and Jewish interpretations involve slightly different wording, all ten laws are morally and functionally identical in both instances. For example the first item in both interpretations refers to placing “No Other God Before Me.” Interestingly both the Christian and Judaic versions, derived from Exodus and Deuteronomy, allude to the fact that loyalty is God’s due for having “brought the people out of the land of Egypt.” The individuals involved in that episode; Moses, Aaron et al. were of course thoroughly Hebrew, and despite their resentment-fueled drift toward pagan worship in the desert, they had no real interest in modifying the Jewish faith, as had Jesus.

Yet over time a common belief system and way of life gave way to the distinction-seeking circuits, leading to persecution of Jews who despite having different rituals, held essentially the same beliefs as the Christians who persecuted them.

The one salient distinction between Judaism and Christianity was of course Jesus’ claim to be God (if indeed that was his claim) which most Jews during the Common Era would have considered blasphemous. Yet even that distinction is somewhat dubious, since Jesus often alluded to prophets like Isaiah and Jeremiah as being in effect, his role models. He pointed out that they too had ascended into heaven, were reborn, and transcended the usual limits of mortality. During the Common Era most Jews held similar views of the higher prophets – and certainly of David.

Even more interesting, in light of the mind’s propensity for integrating and discriminating, are the similarities between Islam and the Judeo-Christian ethic. It is commonly known that the Islamic prophets are, by and large, the same men and women worshipped by Jews and Christians. For example Moslems adhere to the words and deeds of Abraham – whom they call “Ibrahim.” They consider Jesus, whom they call “Eisa al-Masseh” a prophet. They honor the legacies of Moses, whom they call “Musa,” Noah, whom they call “Nuh”, and Isaac, whom they call “Ishak,” and they seem to hold Mary, the mother of Jesus (Maryam in Arabic) in even higher regard than either Christians or Jews.

Despite no direct allusion to the Ten Commandments in the Qur’an Moslems also adhere to the Decalogue, albeit with a few minor revisions. For instance, in “Al-Israa” (The Night Journey) The Qur’an (47:19) states: “There is no other god beside God.” In 14:35 it says: “My Lord, make this a peaceful land and protect me and my children from worshipping idols.” There are also references to not taking the Lord’s name in vain, adhering to the Sabath (though on Friday), honoring one’s parents, abstaining from adultery, murder and theft and from coveting thy neighbor’s wife and bearing false witness.

One possible distinction between the Bible and the Qur’an might be seen in a slightly different wording of one of the commandments. While the Old Testament says: “thou shalt not kill” the Qur’an says in 17: 33: “Do not kill unjustly.”

Could this subtle difference justify the current nihilistic mindset of Islamic extremists intent for so long on exterminating Israelis and infidels in the west? It seems unlikely, especially since some Biblical scholars maintain that in the Old Testament a similar distinction between murdering and killing is implied as well – the argument being that Jews also believed it was occasionally necessary to kill for purposes of self defense and tribal preservation.

With that in mind perhaps history is less a function of time and place than of mind. The Crusades, the current conflict in the Middle East, the war on terror merely a series of plays in the theater of life, staged not by the actors, as Shakespeare maintained, but by a calcium, protein, myelin, water and information containing vessel known as the human brain, during times when the discriminatory aspect of mind took center stage.

A Thousand Years Later…

While the conflict among Christians, Jews and Moslems has continued in modern times we also have an increasingly contentious dispute between proponents of evolution and people of faith. Once again, the question could be asked as to whether this is a real or anthropocentric distinction, and whether, as with The Old and New Testaments and the Qur’an, the similarities outweigh the differences.

I would like to suggest such a possibility, and do so by drawing comparisons between the Decalogue, Al-Israa and the theory of natural selection.

One integrative idea is that the biological mandate revolving around the survival of both the individual and the group, seems to be in agreement with the laws inherent in these religious texts. In order to understand how merely requires a narrowing down and re-categorizating of the commandments into two main bio-moral laws. One espousing altruistic (social, survival enhancing) behaviors or restraints, the other devoted to creating a hierarchical, regulatory structure by which these behaviors and restraints can be prompted and governed over the course of time.

To elaborate; group survival, and by inference, protection of the local gene pool, require cohesion among members. The same cooperative behaviors observed in a pack of lionesses and wolves that enhance survival are also beneficial to human beings. With laws prohibiting theft, murder, adultery and coveting, interpersonal conflict is ameliorated, thus enhancing group cohesion. That dynamic leads to a stronger esprit de corps among members, giving impetus to behaviors that provide for the strong and give shelter to the weak, especially with regard to the protection and care off offspring.

In a bio-moral sense, the Bible and Qur’an are ingenious texts, particularly with respect to one characteristic that typifies all primate groups – the alpha male/female phenomenon. While dominance is often viewed as a bad thing – particularly by those living in a democratic society, it actually works in the primate world. Dominant males protect the members of the group and maintain order by issuing unilateral decisions which are the final word on conflict resolution. The reason this works is based on information dynamics. If all members of a group had equal status and conflict arose, say over territory, there would be no foundation by which to alleviate the conflict other than by mutual destruction. Genetically speaking, that would be an unfortunate trend. Since each member would presume to have equal claim to the territory the only possible endpoint would be a bloody victory by one party over another.

Interestingly, the way this might play out is by one member lining up more supporters than his rivals, thus giving him a numbers advantage in the course of battle. At the point where he emerged victorious, the fact that he had many followers would make him by

definition, a leader – thus setting up a hierarchy in any event. Consequently, in the primate world and perhaps in the mammalian world per se, hierarchies not only work but are perhaps an inevitable by product of socio-mathematics

The problem with humans is that while we also tend toward hierarchies (witness our worship of movie stars, athletes and musicians) we also have a more egalitarian outlook that is perhaps itself a byproduct of human evolution. It results from the fact that our large brains can conjure up so many tools, inventions, artistic configurations and ideas that no single alpha male or female can be sufficient. Thus our species seems to require many alphas.

That creates a potential moral dilemma. Specifically, if power is compartmentalized so that certain individuals protect us from certain hazards but not others – for example a police officer vs. a heart surgeon – there is no overriding arbiter to protect us from broader existential problems or problems that no single person can solve. Beyond that, the powerful can themselves conflict, such that a Brutus can assassinate a Caesar. In such circumstances who then has absolute, overriding authority? Who can decide on matters of conflict and prescribe behaviors and values for all, amidst this broad dispersion of power? Even if abstract laws become the objective solution, there would have to be someone to create and enforce those laws. In other words the combination of inevitable social conflict and the survival-based need for social equanimity in complex human society would perhaps invariably require a transcendent “referee.”

Thus carried to its logical endpoint, the evolution of the human brain from a hierarchy-based and less egalitarian primate brain would inexorably lead to a belief in and need for God.

At face value this conclusion might upset both religious adherents and atheists: the former because it takes God from the spiritual to the bio-natural domain, the latter because it suggests we will never reach a point in our social evolution where we can abandon a belief in some type of God.

Actually neither group need fret over this set of possibilities. First, because it is impossible to know whether natural selection runs contrary to God’s plan or whether perhaps God, in his wisdom has simply given us laws that coincide with the nature He also created which happen to favor survival of the only species capable of religious thought. To suggest there is an inherent incongruence between the idea of a God and the theory of natural selection would be to suggest that God wants us to act in ways that don’t coincide with a world He himself created.

As for the atheists, perhaps nature is all there is. Yet even if that were true, nature would require a lawful foundation, a grounding point by which matter and energy could have formed within the hot, formless plasma known as the cosmic egg. In other words whether or not one believes in a creator, it is difficult to conceive of a universe that began or transitioned from the size of a pin to its current expanse not undergoing some sort of creation process. Even if God doesn’t exist in quite human form, a tenet to which many religions (including arguably Christianity – which views God as a triad consisting of at least two ethereal beings) have always adhered. Does that mean that some overriding regulatory, creative alpha-component (say for example a superstring or particle constant that one day might be called the “El” particle) doesn’t exist and cannot work its wonders by transcending the rest of nature? I suppose it would depend on which part of our brain was in play at any given point in time.


Cromwell, & Schultz (2003) Effects of Expectations for Differential Reward Magnitude

on Neuronal Activity in Primate Striatum. Journal of Neurophysiology 89: 2823-2838

Freud, S. (1960) The Einstein-Freud Correspondence; From; Einstein on Peace O.H Nathan & H, Norden (ed) New York; Schocken Books 186-203.

Jefferson’s Religious Beliefs, Research and Collections, Montecello Research Dept. Aug 2007

Mercado, E (2008) Neural and Cognitive Plasticity: From Maps to Minds. Psychological Bulletin, Vol. 134, No. 1 109-137.

Perry, B. (2008) Aggression and Violence: The Neurology of Experience. 1-2.

Qur’an: 47:19

Qur’an: 14:35

Qur’an: 17:33

Wilson, M. & R. Wrangham. (2003) Inter-group Relations in Chimpanzees. American Review of Anthropology 32: 363-392

By: Robert DePaolo

Saturday, November 21, 2009

Tuesday, November 17, 2009

Myth, Stanislavski and Mirror Neurons

"Art is the clothing of a revelation
." Joseph Campbell.

“Truth in the theatre must be genuine, not glamorized. It must be purged of unnecessary, mundane details. It must be true in a realistic sense but made poetic by creative ideas.” Konstantin Stanislavski

“All the most powerful ideas in history go back to archetypes. This is particularly true of religious ideas, but the central concepts of science, philosophy, and ethics are no exception to this rule. In their present form they are variants of archetypal ideas created by consciously applying and adapting these ideas to reality. For it is the function of consciousness not only to recognize and assimilate the external world through the gateway of the senses, but to translate into visible reality the world within us.”
Joseph Campbell

Abstract: Stanislavski intuited human truths that scientists are still grappling to describe. Recently scientists have begun to prove what Stanislavski discovered without the aids of fMRI machines or advanced chemistry. This paper is an attempt to describe my own wrestling with neuroscience and mythology; ideas to which I believe he would have been attracted, .

As a passionate theatre practitioner, I believe that the most fundamental use of our ancient art form is the reconciliation of humanity with itself, with the gods, and therefore with the natural and metaphysical world. Theatre, for me, is not necessarily what happens in a designated performing space; it occurs whenever an “actor” and an “audience” willingly appear. This coming-together-spilt, this dualism, exists for a certain amount of time, and when it disappears the two parts leave each other altered as a result of the encounter.

The quality of live theatre involves a sensual, nearly fleshly exchange between the spectators and the actors. Whether behind masks as for the ancients, or behind grease paint, or naked-faced, actors exist biologically in the same space as the audience but separate from it. As the brilliant British director and acting theoretician Declan Donnellan says, “A theatre is not only a literal space, but also a place where we dream together; not merely a building but a space that is both imaginative and collective”. (Donnellan, 2006)

This very fact, that audiences and actors encounter dreams in a shared space, means that the perceptions of the audience are capable of actual physical involvement with the play itself. They could, if provoked, storm the stage and take over, or depending on the size of the house, they might be able to grab the apple the actor is eating. Luckily for most actors, the audience is content to watch and vicariously experience eating the apple. Theatre practitioners have always known that the audience is in someway moved and affected by the actions of the characters passing before them. The idea of catharsis implies cleansing, in which tears and laughter are physiological responses. However, there are less obvious responses that we actors and audiences have always been aware of that go beyond these outward shows. Stanislavski, when speaking to actors, remarked on an energy that seemed to pass between people in the following quote.
“. . .Haven’t you ever been aware, in life or onstage, when in communication with other people, of a current emanating from your will flowing through your eyes, your fingertips, your skin? What shall we call this method of communication? Emitting and receiving rays, signals? Radiating out and radiating in? In the absence of an alternative terminology let us stick with these words since they illustrate very clearly the kind of communication I have to talk to you about. In the near future, when this invisible current has been studied by science, a more appropriate terminology will be established.” (Stanislavski, 2008)

In his search to find natural and scientific ways of looking at acting, Stanislavski predicted the findings encountered in a laboratory in Parma, Italy in 1996 by a team of neurophysiologists. This team was studying the brain responses of Macaque monkeys when grasping objects with their hands.

“ . . . the neurophysiologist, Vittorio Gallese was moving around the lab during a lull in the day’s experiment. A monkey was sitting quietly in the chair, waiting for her next assignment. Suddenly, just as Vittorio reached for something--he does not remember what--he heard a burst of activity from the computer that was connected to the electrodes that had been surgically implanted in the monkey’s brain . . .Vittorio immediately thought the reaction was strange. The monkey was just sitting quietly, not intending to grasp anything, yet this neuron affiliated with the grasping action had fired nevertheless.” (Iacoboni, 2008)

What this meant was undeniable; the idea that monkey see, monkey do “virtually” is true. The monkey was observing and experiencing what the researcher was doing and responding to it biologically. These neurons are now referred to as mirror neurons (MNs).
Since this discovery much effort has been put into examining the human implications of this phenomenon. Researchers have recently confirmed that the same neurons exist in people and are spread widely across the brain. (James M. Kilner, 2009) There still exist many questions concerning the limits of MNs. We know that they are closely related physiologically to Broca’s area, the central area for speech production and language understanding in the brain, but we don’t yet know if this positioning has any relevance. Scientists also hypothesize that this system of neurons is responsible for a more complex emotional empathy and recognition of emotional states in others. (Ramachandran, 2007) However, given the simplest understanding of mirror neuronal activity, we can say that while the audience member doesn’t grab the apple, in a sense his body does. The same signals are sent to the same muscles the actor uses to grab the apple. What prevents the audience from charging the stage for the food is a shut-off valve in the spinal cord that knows the difference between virtual and actual. (James M. Kilner, 2009)
Furthermore, these mirror neurons are excited not only by the action, but also by intention. (Ramachandran, 2007) The viewer’s body fires as he observes the intention, before the action is fully completed. Without seeing intention, the viewer remains as passive as the person sitting by the apple or the monkey in the cage; it is only when the actor intends to pick up the apple that the chemically-electrically charged neurons explode. Studies have also shown the likelihood of the same sorts of involuntary brain responses to sounds and primal facial expressions. Once again, the more familiar the action, the more likely it is to light up our circuits.

What all of this indicates is that we as humans respond physiologically to familiar situations that because of their familiarity have the power to engage us on a bio-chemical level. Is this physiological connection to another, this “sparking” of each other as it were, the thing that actors and audiences sense in the air? Of course there are other physiological responses besides actions and intentions that contribute: the thrill of the sounds of language, lights, colors, music; all processed differently in the brain. But neuroscientists are beginning to hypothesize that MNs are the site of emotional empathy and, like the muscular response, the chemical response to another’s pain or pleasure is also “virtually” experienced in the body of the viewer. (Ramachandran, 2007)

With this in mind, the concept of separate selves begins to depart, and a communal experience begins, everyone firing neurons, some more brightly and some less, depending on their world experience. The selves of the audience begin to dissolve and an expansion of possibility begins. (Bulinska, 2007)
In accepting his Oscar, the actor, Forest Whitaker said:
“. . . when I first started acting, it was because of my desire to connect to everyone--to that thing inside each of us. That light that I believe exists in all of us. Because acting for me is about believing in that connection and it's a connection so strong, it's a connection so deep, that we feel it. And through our combined belief, we can create a new reality.” (Biilington, 2007)

The theatre, sport, and religion all become a means for us to re-visit cast off dreams, innate heroic possibilities and other selves that we left behind in childhood; to be re-united with a half-remembered potential if only for a while. The left-behind others about whom I speak, include not only our mourned-for frail other-selves, but all of the strong, single-minded appetites and values on which we might have built alternative lives and identities, the tyrants, the pedants, the seekers of truth, the mischief makers, the athletes, the saints, the hedonists, the builders, the martyrs, the torturers, the dancers, the executioners, the sensualists, the explorers, the madonnas, the gluttons, the criminals, the lovers. They include the lions and tigers and monkeys and snakes and eagles and elephants and coyotes and dogs we could have been.

These qualities of ravenous need and curiosity emerge from our bodies and our survival instincts; however civilization has tamed these potentially harmful impulses. Our bodies continue to experience these desires for action, but our need to remain safe, protects us from anarchy. The MN activity must suffice for us. The archetypes familiar to us from the legends of many cultures are hardwired and given faces in our unconscious world. The names we give to these gods/archetypes/heroes vary depending on issues of geography and economy.

In his search for the underlying principles of mythology, Joseph Campbell agrees with Carl Jung that myth was an outcropping of such dreams; dreams formed involuntarily by the sleeping brain. Campbell’s discovery that the symbols in dreams were universal led to his belief in the collective unconscious.

“Carl Jung describes archetypes as innate universal psychic dispositions that form the substrate from which the basic themes of human life emerge. Being universal and innate, their influence can be detected in the form of myths, symbols, rituals and instincts of human beings. Archetypes are components of the collective unconscious and serve to organize, direct and inform human thought and behaviour.” (Campbell 1972)

An archetype can therefore be understood as the embodiment of a natural power, either animal, human, or some variation therein. As with all power, if the source of the energy is not able to be experienced in a sensory way, it does not appear to be present. We as humans seek ways to envision these emanations through stories and characters wherein the powers collide and intermingle. We need to find a container for these explosions, a human way of envisioning non-embodied energies. For me, these are the archetypes most useful to actors. The stories that emerge are what we refer to as myths. For the power of the myth and its attendant archetypes to be of use to society, rituals are created as needed by a given community to either assuage or contain energies that might destroy the group if left to their own devices. Mircea Eliade’s main concept is that ritual is a way for a given society to move safely from one disruption of the group’s wholeness to another. (Eliade,1963)

Religion and theatre provide spaces for a communal unification to happen in an actual and a metaphoric way. Both are ways to connect physically, intellectually, and emotionally with our culturally defined archetypes alongside other equally disconnected humans. The rituals performed by the actors and priests with their music, movement, and words serve to unite us with the powerful symbols of our archetypes, and aid in acceptance of the helpful and rejection of the hurtful. The rituals repeat symbolically the old stories, sometimes literally, sometimes metaphorically. Often the metaphor is lost to the participant, but there is still comfort in its very being, because the meaning takes place in his musculature. The MNs fire, the images impress, the music is heard.

If we see the ritual as a journey from one point to another wherein a human being/hero confronts powers that are externalized in the ritual through symbols as well as other beings, both human and quasi-human, it becomes apparent that a play is a ritual for the audience whether sought as such or not. Joseph Campbell has codified this transformation as “The Hero’s Journey.”
Both theatre and religion repeat the old stories; that is a major part of their ritual function, but only the theatre intends to irritate us with new questions about the old stories. Even when it has no political or sociological ax to grind, its function, besides ritual, is that of investigation into what makes us human and how to interpret the world around us.

The actors, who are already initiated into the mystery of the play, must lead the audience through this ritual terrain. As the audience views the journey, their mirror neurons and entire sensory system must become so excited through the actor’s actions in these confrontations that they are re-united with themselves and altered in some way. They must be taken to a place of unity. James Joyce’s concept that the spectator must be arrested, must lose a sense of self in the presence of “proper art,” is an attempt to describe this phenomenon. (Joyce, 1916)
There are a finite number of stories. I am aware that there are only thirty-six plots, or twelve, or four depending on your reference. (Polti, 1917, McKee, 1997) If one also understands that there are only six or seven essential relationships based in kinship and community, one can easily see that (given some arithmetic beyond my capabilities) all the new scripts are simply eternal themes and heroes dressed in contemporary clothing.

As a trainer of actors, this brings up many questions.
(1) How can we best enable actors to take the audience along with them on the journey of the play?
(2) How can we enable actors to discover the powers within themselves necessary to work on an embodied level of such strength and commitment to primal action that not only their fellow actors, but also their viewers will be moved on a biological level?

(3) How can we best provoke our actors to move beyond the temporal trappings of the story to find the power of the myth beneath?

It goes without saying that such actors must be vocally and physically flexible, strong and imaginative within those systems. However, we frequently neglect to create actors who are large enough imaginatively, intellectually, and spiritually to take on such a task. In fact, we have conflated the idea that an actor “shouldn’t be in his head” with a rejection of the need for curiosity and intellectual exploration. How can we re-awaken ourselves, and our students in order to re-examine what we mean by the word Theatre?

In my attempt to find a way to a theatre that matters on a universal level, peopled by actors whose work is selfless and inspiring, I have greedily searched the works of any serious writer who addresses myth, ritual, philosophy, acting, psychology, sociology, neuroscience, and anthropology. Among these are Joseph Campbell, Karen Armstrong, Richard Schechner, Leonard Shlain, Ernest Becker, Jerzy Grotowski, Antonin Artaud, Declan Donnellan, Victor Turner, Karen Armstrong, Konstantin Stanislavski, Carl Jung, Francisco Varela, Antonio Damasio, Marco Iacoboni, Evan Thompson, Bill Ball, Mihaly Csikszentmihaly, Michael Gazzaniga and many, many others.

My hypothesis is that our mirror neurons are more excited by intentions that are corporeal, primal, and emotionally imbued. We have a good deal of evidence that MNs respond to emotional states and for me the purest forms of these emotionally charged actions are contained in myth, archetype, and ritual.

In order to test this idea I decided to begin at the beginning and attempt to discover how this might work for actors. If the world begins in chaos, if human development is an attempt to tame wildness both within and without, it seemed appropriate to thrust my students into chaos. Mihaly Csikszentmihaly's flow theory of creativity and learning suggests that the process of learning proceeds from frustration to mastery to boredom and thence onto further frustration. (Csikszentmihalyi, 1990) Frustration from this point of view can be seen as chaos and so, at the top of the syllabus for this class, I include the following:
The flow of learning proceeds from frustration to mastery to boredom and back to frustration in a continual upward moving spiral encompassing greater and greater circumference. Frustration therefore is to be desired and mastery should be considered a transitory state. The circumference encircles more and more of the world of ideas and spiritual understandings in the dance of consciousness. Welcome! (Brody 2005)

I challenge myself to allow this frustration, even when it results in complaint, confusion, pouting, and general grumpiness amongst the acting students. My objective is to provoke the aspiring artists to rely on each other and their own ingenuity to create whatever pieces they are working on.

In order to prepare them for what is coming in the first and most important quarter of this year-long acting class, all students are notified during the summer that they are expected to read Joseph Campbell’s The Hero with a Thousand Faces (Campbell) and Peter Pan (Barrie). I strongly encourage them to attempt Ernest Becker’s The Denial of Death (Becker) as well. While many academics may find this easy reading, it is not considered so by the actors, it is frustrating. By being forced to grapple with material that seems to be just out of their reach, they come into the first quarter excited and popping with ideas and questions.

We spend the first several weeks simply discussing mythology, heroes, archetypes, Freud, religion, symbols, as well as the ways in which dramatic structures do or do not follow the hero’s journey as delineated by Campbell. I contribute data from neuroscience, biology, psychology, and anthropology using articles and readings concerning memory formation, image creation, and mirror neurons. We investigate the differences between female and male journeys and debate whether these journeys were a result of biological determinism or social constructs. And of course, Aristotle, Plato, Nietzsche, Christ, Buddha, and others begin to enter our conversations. My focus during this time is to challenge their imaginations, to expand their view of themselves as intellectual beings, and to begin to create a synthesis between practical acting work, neuroscience, and universal ideas. The actors begin to feel proud of themselves for tackling such supposedly difficult topics, they begin to look for more answers, some branching out into different inquiries. One student who had broken away from a fundamentalist black church decided to investigate the idea of ecstatic states as revealed in talking in tongues. Another became fascinated with the ideas of sex and death. It is not uncommon for the students to read Mirroring People by Marco Iacoboni, return to the The Denial of Death, read widely in more widely in philosophy and mythology. Some become genealogists.

The first assignment of the quarter is to create a seven-minute solo performance piece using as many theatrical forms as possible, music, dancing, mimicry, simple props, costume, and spatial placements. The actors are instructed that the story must be told theatrically, not as a direct narrative, and that whatever the story is, it needs to be seen as one of the stops in a hero’s journey. It has to be based on a family legend using their own grandparents or other ancestors. It involves examining how such stories become a part of family lore, how they shift and change through retelling, how the actual event becomes lost in the elevation of its meaning, and how the ancestor becomes a representative of a family archetype. In addition to challenging/frustrating the actors, my objective is for the actors to understand on a personal level how myths and archetypes, that heretofore have seemed a distant, dead idea lodged in the Greek Pantheon, are ever-present in our lives.

These small pieces are usually interesting glimpses into the actors and their processes. They create a wonderful teaching opportunity to discuss structure, clarity, physical and vocal flexibility, importance of specific choices, and ways in which conflict is necessary for growth. The only critique given involves whether the actor did or did not communicate what they intended. The class is asked to examine whether they felt involved biologically/neuronally/emotionally or whether their attention had wandered. Were they aware of subtle physiological changes in their own bodies? I avoid speaking about the piece myself, preferring to wait until the other students in the class speak about the work. The performer was not allowed to verbalize until after his classmates had tried to wrangle out the meaning amongst themselves of what they just witnessed. This discussion allows the performer to hear what the audience saw and felt without defending or explaining the work. He or she begins to understand the necessity for fulfilled, intended gestures both psychological and physical, and for the absolute requirement of a clean demarcation of events. The performers also begin to develop a healthy respect for the audience’s attempt to attach meaning to whatever movement, prop, costume, or set piece is on the stage.

We do not repeat these pieces because I don’t want them to take on too much importance for the actors. They are etudes where hopefully learning takes place for both viewer and actor without the pressure of judgmental evaluation. They are ways for the actor to begin to contemplate his or her part in a large story.

From here we move on to Peter Pan. (Barrie, 1992) The reason for using this supposed child’s story is to employ the range of archetypal characters, to play with the idea of dreamscapes, and to examine the concept that the basis of all relationships are grounded in the conflict between order (Wendy) and chaos (Peter). Within Peter Pan we examine the significance of earth versus sky, water versus land, inside versus outside, male versus female, natural versus civilized, child versus adult, animal versus human, and many, many other binary ideas. At this time, I usually introduce Babylonian creation stories, androgynous gods, Jungian ideas of anima and animus and dream symbolism.

My challenge to the class is to create and enact one scene from Peter Pan in twenty minutes with whatever props or attire is present in the studio. (I usually sprinkle the room with things for them to find, scraps of material, bags, canes, balls, ropes, nets, old costumes and so forth). I leave the room and go to my office. (By some report, this twenty minutes is probably the most frustrating of all for the students). What on earth do I want them to do? What am I looking for? How could they do this well? When I return, the actors have for the most part given up the desire to please me. They have decided to simply present their story, and have formed a pact to do whatever is necessary for this bizarre assignment. However, they are also excited and turned on by the group’s creation. Once again, my aim in this exercise is to reawaken a spirit of play with the pressure of time serving to necessitate structure. They present their muddled but passionate rendition of the story, and after praising the attempt, I ask questions of intent and meaning. What did they want me to see, or understand, or feel? What powers/archetypes are present in the scene? What rituals? How did they process what the others were doing? Might the archetypes in the scene be clearer, fuller, more primal? Who exactly are the mermaids? Who are the pirates? What is the water? What is the boat? How is this related to dreams? It takes a bit of probing and encouraging, but sooner or later, their imaginations begin to bring forth better and more interesting ideas. (Ball, 1984) As soon as I sense excitement and desire to do the scene again, I absent myself once more, giving them thirty minutes to work on the project. And so it goes. The work becomes deeper, less clever, and cleaner as the actors search for better ways of telling the story. Participation in the group becomes stronger and the desire to create theatre can be palpable. The actors begin experimenting with stereotypes and more meaningful archetypes, they include more dancing and singing and the presentation becomes less predictable.

The next class is an attempt to tell the entire Peter Pan story without the script. For this to happen, we use a titled scenario list, which I have created based on the scenes in the play. I e-mailed it to them separately the evening before and it is either written on the blackboard or near at hand in the room. I give them an hour to work out whatever they deem necessary and return to view their attempt. These scenes are never graded or appraised as products; they are a means of embracing chaos, impulse, instinct, feeling in the dark, jumping off cliffs, and a certain kind of sloppiness. It might be said that this recklessness encourages failure, but when success is not an aim, failure is not a possible result.

By this time in the quarter, the actors are generally having a wonderful time, but are beginning to feel confused. What is the result of our work going to be, is our time being well used, shouldn’t we be memorizing lines and blocking yet? It is a delicate time for all of us. For me it is a leap of faith. I have to trust that my theory is somehow correct, and they have to bear the frustration of open-ended work.

It is at this time that we move toward scripted scenes as delicately as possible. We begin a process scenes that has been given the name SuperScenes by my students. A SuperScene reveals the primal energies, archetypes, and essential conflicts that underlie any scene. It is an attempt to investigate the scene beyond its temporal elements, beyond the "characterized" elements and plot-based ideas, and into the universal questions, energies, conflicts, and archetypes that are the original patterns for all scenes.
As V.S. Ramachadran says, “Art involves distortion, hyperbole and exaggeration... A specific type of distortion... Sanscrit word rasa, the spirit of something, the soul of something, capturing the very essence to evoke a specific emotion in the viewers brain.”(Ramachandran, 2001)

They have all read and discussed Angels In America, Part Two: Perestroika (Kushner, 1992) not only for this class, but in their history and criticism class. The territory has been covered, so the actors feel a bit more settled. The scenes I choose to use are are Prior’s first confrontation with the Angel, the subsequent conversation with Belize, and the angel committee scene in act four, scene five. All members of the class are involved.

The angel committee scene is especially ornery and in the preface to one of the three published versions of the play. But it offers the ability to work as a quasi-chorus, to experiment with archetypes, and to move beyond literalism and into metaphor. Who are these angels? What is this scene about? Where is it set? What is at stake? Kushner offers few hints, but as a poet, the clues he leaves are creatively rich.
The work now turns from entirely improvisational to textual. The actors use the lines of the script, although during the early days of these explorations they are allowed to riff into song or quotation if the desire arises. The rest is up to their imaginations; they are responsible for deciding upon the archetypes and how they will enact them. They decide where the scene takes place. They are encouraged to fully enact any metaphor that emerges. They are not required to pick up lines, to interpret lines, to fulfill any blocking. They are required only to play.

As usual, the first several attempts are rather formless, stabs in the dark, lots of mugging, un-needed movement and difficulty finding something “to play.” But one by one, each actor finds an archetype with which they feel comfortable and which more or less gets at the deeper meaning of the role itself. In the latest incarnation of this, one of the actors became a Super Handyman because he had to deal with the radio so frequently, another who found the language of his role dense but un-emotional became a Mathematician/Scientist, one of the women became Cassandra, and another, an Orphan adrift. One of the actors began as a Gorilla and another, a Crabby Old Man Critic. As the scene progressed, they began to discover which of the other actors seemed to be on their side in the arguments. They started bringing in objects, hand props, costumes, and other items to help in the work.

As entertaining for all of us as this was, few of them were affected by it beyond some rather generalized emotion. They ran at the scene, tried to knock it down to size, and were always less than happy with the result. Finally, in one of their rehearsals, they decided that the radio and its emanations was the problem. No one was able to fully invest it with much meaning. So they asked their fellow actor who had been reading offstage to come onstage and become the radio. The stage, which heretofore had been a rather nebulous space, transmogrified into a sort of lifeboat, with everyone waiting to hear the news of possible rescue. All actors became intently focused on the Radio/Man who proceeded to choke and return to life and again fight for breath. As the Radio/Man sputtered, the Handyman became a Desperate Surgeon trying to resuscitate the dying patient, the Mathematician/Scientist became a Guide for the Surgeon, Cassandra wept because of what she knew, the Orphan hid from death and the Old Man facing the falling away of his ability to communicate with the outside world began to weep for his own demise. The Radio/Man finally breathed his last and was dropped into the sea. All began to weep, mourning their impotence, and little by little they began to blame, to rationalize and to argue amongst themselves. The Tower of Babel was in front of me as they talked over and beyond each other in panic.

As the Angel of America came into the scene of chaos accompanied by the Prophet Prior, everyone stopped at once and looked to them for rescue. Prior attempted to give back the angelic book, and refused take up their petition. Several implored him to hear their plea, but in his need to save himself from going down with the ship, he deserted them by picking up the fallen Radio/Man and walking off stage with the body over his shoulder.

There was a silence in the room after this as the actor’s collected themselves and prepared to do the scene immediately again as the assignment for the day had stipulated. This time was to be the “Real Scene.” It was to be transported to contemporary time, and to a boardroom of sorts for the Committee of Angels. They quietly put on coats and ties, suit jackets and high heels. There was some little talking, a bit of joking, but everyone remained in the emotionally available state needed for the scene. Several of them set up our much-used movement mats to create desks, and the room configuration changed from a centrally located lifeboat to a wide V-shaped conference table with two chairs at the top of the V behind a metal table connected to the mat/desks each of which had three chairs. The metal table held the radio (they used a theatrical lighting fixture). The only addition was a series of open road maps in front of each chair. When all was ready they began the “Real Scene.” The effect was magical. The repression of all that power, and wailing, and death was replaced by the coolness and status-seeking atmosphere of such a place. The stage was full of almost visible energy, of full consciousness, of attention, and of adjustment to the new circumstance. I could feel the air vibrating between them.

The roles changed, but the archetypes remained hidden behind the etiquette of the business meeting. The questions and insights that arose from this exercise were deeply significant. How does the relationship between the sexes change in such a setting? In the SuperScene, all seemed to have equal power and were unconcerned about their place in the scheme of things. However, when the suits went on, “soft” things such as grief, empathy, fear of the unknown, were protected behind the corporate armor.

The two men at the “head table” happened to be wearing suit jackets, and the two actors on the sides had neglected to bring jackets on that day. It made an enormous difference to the jacket-free men, they reported feeling unready for the battle. Jockeying for power became tantamount, jealousy and judgment and sarcasm flew around the room. The Grumpy Old Man Critic, turned into a younger Wise Ass, sitting, jacket free, at the very end on one side of the table. At the discussion following the scene, he expressed his feeling that he was unimportant not only because he was seated at the end of the table, but also because he was separated from the other men by the two women seated to his right. He also mentioned that he began comparing his tie to those of the other men.

The women, more than the men, seemed to have difficulty adjusting to the new environment. As the men became much less expressive and more verbal, the women began to take a quieter role. They, Cassandra and the Orphan, joined forces, the Orphan becoming a Experienced Businesswoman in the world of men, and Cassandra, a Junior Woman Executive mostly silent and looking to the Orphan for security. The awareness of the need to suppress feelings of compassion, gentleness, and fear of the unknown, took over.

The former Gorilla became a rather watchful Junior Executive, seated at the right hand of the Scientist and the Handyman quietly trying to assess his role in the situation. In this situation, the former King of the Jungle, became a Watcher in the Thicket, still a gorilla, but made impotent by his inability to adjust to technology.

The two men sitting in the middle, the Handyman and the Scientist, both jacketed, had direct access to the actual radio. They became the focal point of the meeting because of their supposed technical know-how. The Handyman, now a Technician, a sort of Second in Command to the Scientist, tried to use his body as an antenna reaching out for the current, moving from side to side, and at one time hitting the radio. The Scientist disdained the Handyman’s attempts preferring to quote facts and figures as a way of gaining status.

As the radio died, the committee broke into heated debate, everyone vying to make their personal point be heard. Tempers flared, disdain was in the air, and then the Angel of America entered the room, rather confused by the noise she had obviously heard outside the door. She came without Pryor, announced his coming, and went back out into the hall to fetch him. She had morphed from a powerful albeit limited Fiery Angel/Emissary to a rather anxious Casting Director who was going to present her latest talent discovery to a group of powerful and fractious television executives seeking to save the studio.

The Angel/Casting Director returned with Pryor, formerly a contorted and bandaged Leper, now a Conscientious Objector/ Actor attempting to return an unsavory script while remaining in favor with the Big Shots. The Angel who had heretofore not realized that she had a vested interest in his success, watched his every move now because her future also depended on his success at the meeting. When he could not be persuaded to accept the role, she attempted to help him, first by argument and challenge, and finally by acceptance of his choice in life. She mourned with him about the ultimate tragedy about to beset them all. As he petitioned for a blessing he became weaker and weaker, falling to the floor and righting himself. He fought to maintain his uprightness both physically and ethically.
Cassandra finally had to leave the table, but was stopped in mid-track by the Scientist who (as he later reported) was not going to let her get away so easily. The Orphan attempted to comfort him, the Scientist ridiculed him, the Handyman couldn’t figure out what to do with him, the Wise Ass confronted him, and the Gorilla sought refuge behind the Handyman. As Pryor declared his independence of both the committee and God, he picked up the maps and folded them in symbolic preparation for his journey. The Scientist refused to give him the map and Cassandra hid the map on her person.

At last we had achieved what we had set out to do, metaphors piled on top of symbols, shifting archetypes within a realistically played scene. The ancient stories were obvious in the power plays, the sexual politics, the fear of death, the importance of denial, the sins of the fathers visited on their children, the clash between order and chaos. Contemporary problems appeared in the demise of our ability to understand or alter technology and our reliance on experts. The symbolism of the Handyman trying to channel a capricious and unknown energy was powerful. Many issues were touched upon: the chimera of human power, the revelation of the Wizard of Oz behind the curtain, the paradox of striving for life with full knowledge of death. In our little classroom, they had moved through play towards Joyce and Aristotle with actions that excited them physically and emotionally.

From this point forward all of our scenes are rehearsed first as SuperScenes and when we feel that we are ready we jump into the “Real Scenes.” There are times when the SuperScene is better than the Real Scene, depending on the playwright. This has been very true with Suzan Lori-Parks and Sam Shepard. SuperScenes awaken the actor and the director in such a way that the need for blocking or beat-by-beat script analysis becomes a rather secondary exercise, good for cleaning up and reference. And yet, the SuperScene does not negate nor tamper with the script; we honor the playwright by our thorough investigation of the play from a philosophical, universal level;we maintain the structure of the scene. The changes we bring to the play are in the attempt to widen the ability of the audience to receive it on a more visceral level. We strive to make theatre.

Ball, W., 1984. A Sense of Direction: Some Observations on the Art of Directing, first ed.: Quite Specific Media Group, Ltd.
Barrie, J.M., 1992. Peter Pan or The Boy Who Would Not Grow Up. A Fantasy in Five Acts New York: Dramatists Play Service.
Becker, E., 1973. The Denial of Death New York: The Free Press, a division of Simon and Schuster Inc.
Biilington, A., 2007. Post-Oscar: Forest Whitaker's Brilliant Acceptance Speech [online].
Bulinska, H., 2007. Mirror neurons as a proximal mechanism of social interaction. Conflict, Citizenship and Civil Society, 8th ESA Conference, European Sociological Association. Glasgow Scotland.
Campbell, J., 1972. The Hero with a Thousand Faces Princeton, NJ: Princeton University Press.
Csikszentmihalyi, M., 1990. Flow: The Psychology of Optimal Experience New York: Harper Perennial, HarperCollins Publishers.
Donnellan, D., 2006. The Actor and the Target second ed. London: Theatre Communications Group.
Eliade, M., 1963. Myth and Reality first ed. New York: Harper and Row.
Iacoboni, M., 2008. Mirroring People New York: Farrar, Straus & Giroux.
James M. Kilner, A.N., Knkolaus Weiskopy, Karl J Friston and Chris D Frith., 2009. Evidence of Mirror Neurons in Human Inerior Frontal Gyrus. The Journal of Neuroscience, 29.
Joyce, J., 1916. A Portrait of the Artist as a Young Man B.W. Huebsch.
Kushner, T., 1992. Angels in America, Part Two: Perestroika New York: Theatre Communications Group.
McKee, R., 1997. Story: Substance, Struture, Style and the Principles of Screenwriting New York: HarperCollins Publishers.
Polti, G., 1917. The Thirty-Six Dramatic Situations Ridgewood, New Jersey: The Editor Company.
Ramachandran, L.M.O.A.V.S., 2007. The Simulating Social Mind: The Role of the Mirror Neuron System and Simulation in the Social and Communicative Deficits of Autism Spectrum Disorders. Psychological Bulletin, American Psychological Association, 133, 310-327.
Ramachandran, V.S., Freeman, A, 2001. Sharpening up 'The Science of Art'. Journal of Consciousness Studies, 8, 9-30(22).
Stanislavski, K., 2008. An Actor's Work London: Routledge Press.

The Words You Choose in an Argument Can Literally Break Your Heart « N e u r o n a r r a t i v e

I found this interesting in light of Reason to Be Pretty, and Moira's comment about language during rehearsals. People with less ability to express themselves really do hurt themselves. The Words You Choose in an Argument Can Literally Break Your Heart Jump to Comments arguingIn the middle of a fight with your significant other, word choice is usually not foremost on your mind. But it should be, particularly if you’re a man, according to a new study in the journal Health Psychology – and not just to save your partner’s feelings. In the heat of stressful conflict, your brain is commanding the release of a stress-chemical cocktail comprised of proteins called cytokines–produced by cells in the immune system to help the body mount an immune response during infection. Abnormally high levels of these proteins are linked to cardiovascular disease, type-2 diabetes, arthritis and some cancers. This study suggests that how rational or emotional your communication is directly corresponds with the levels of those chemicals in your body and the damage they can do. Forty-two couples made two separate overnight visits to the study lab over two weeks. During their first visit, couples had a neutral discussion. During the second visit, couples focused on the topic of greatest contention between them. Research interviewers figured out ahead of time what made the man and woman most upset in terms of their relationship and gave each person a turn to talk about that issue, thus igniting the conflict. During an argument, people tend to use two categories of words: emotionally charged and cognitive. Emotionally charged words come easily when angry and many of them have just four letters. Cognitive words such as “think,” “because,” “reason,” and “why” indicate that the participants of the conflict aren’t lost in rage. They can still make sense of the issues and are more likely to arrive at a resolution. Researchers measured the levels of cytokines before and after the two visits and used linguistic software to determine the percentage of certain types of words from a transcript of the conversation. The results suggest that people who used more cognitive words during the fight showed a smaller increase in cytokines. Cognitive words used during the neutral discussion had no effect on the cytokines. When researchers averaged the couples’ cognitive words during the fight, they found a low average translated into a greater increase in the husbands’ cytokines over time, but not an increase in wives’ levels. Researchers speculate that the reason for the discrepancy is that women may be more adept at communication, and perhaps their cognitive word use had a bigger impact on their husbands. Women in the study were also more likely than the men to use cognitive words. The big takeaway: choose your words carefully and keep the emotion in control when arguing. Over time (fellow men especially) we pay the price for losing ourselves in the fog of fury. Graham JE, Glaser R, Loving TJ, Malarkey WB, Stowell JR, & Kiecolt-Glaser JK (2009). Cognitive word use during marital conflict and increases in proinflammatory cytokines. Health psychology : official journal of the Division of Health Psychology, American Psychological Association, 28 (5), 621-30 PMID: 19751089 hat tip: EurekElert

Thursday, November 5, 2009

Limits of empathy?


R.I.M. Dunbar
Human Evolutionary Biology Research Group
Department of Anthropology
University College London
London WC1E 6BT


Neocortical size, group size, humans, language, Macchiavellian Intelligence


Group size is a function of relative neocortical volume in nonhuman primates. Extrapolation from this regression equation yields a predicted group size for modern humans very similar to that of certain hunter-gatherer and traditional horticulturalist societies. Groups of similar size are also found in other large-scale forms of contemporary and historical society. Among primates, the cohesion of groups is maintained by social grooming; the time devoted to social grooming is linearly related to group size among the Old World monkeys and apes. To maintain the stability of the large groups characteristic of humans by grooming alone would place intolerable demands on time budgets. It is suggested that (1) the evolution of large groups in the human lineage depended on the development of a more efficient method for time-sharing the processes of social bonding and that (2) language uniquely fulfills this requirement. Data on the size of conversational and other small interacting groups of humans are in line with the predictions for the relative efficiency of conversation compared to grooming as a bonding process. Analysis of a sample of human conversations shows that about 60% of time is spent gossiping about relationships and personal experiences. It is suggested that language evolved to allow individuals to learn about the behavioural characteristics of other group members more rapidly than is possible by direct observation alone.

1. Introduction
Primates are, above all, social animals. This has inevitably led to the suggestion that such intense sociality is functionally related to the exceptional cognitive abilities of these animals, as reflected in their unusually large brains (Jolly 1969, Humphrey 1976, Kummer 1982, Byrne & Whiten 1988). This claim is supported by the finding that mean group size is directly related to relative neocortical volume in nonhuman primates (Sawaguchi & Kudo 1990, Dunbar 1992a). These analyses suggest that although the size of the group in which animals live in a given habitat is a function of habitat-specific ecologically-determined costs and benefits (see for example Dunbar 1988, 1992b), there is a species-specific upper limit to group size which is set by purely cognitive constraints: animals cannot maintain the cohesion and integrity of groups larger than a size set by the information- processing capacity of their neocortex.
The group size identified by this relationship appears to refer to the maximum number of individuals with whom an animal can maintain social relationships by personal contact. It is not necessary that all these individuals live in the same physical group: chimpanzees (among a number of other species) have a fission/fusion form of social system in which at any one time the community (the group in the sense defined above) is divided into a number temporary foraging parties whose composition changes repeatedly (see for example Wrangham 1986). Nor does it follow that a species' social system consists only of a single type of group: it is now clear that most primate species live in complex multi-tiered social systems in which different layers are functional responses to different environmental problems (e.g. the gelada and hamadryas baboons: see Dunbar 1988, 1989a). Rather, the neocortical constraint seems to be on the number of relationships that an animal can keep track of in a complex, continuously changing social world: the function subserved by that level of grouping will depend on the individual species' ecological and social context.
It is important to appreciate that the causal relationship between group size and neocortex size depends on the explanatory perspective (or level) adopted. In evolutionary terms, the size of a species' neocortex is set by the range of group size required by the habitat(s) in which it typically lives. However, seen in proximate terms from an individual animal's point of view, current neocortex size sets a limit on the number of relationships that it can maintain through time, and hence limits the maximum size of its group. This means that although the evolution of neocortex size is driven by the ecological factors that select for group size, we can use the relationship in reverse to predict group sizes for living species (Dunbar 1992a).
It is generally accepted that the cohesion of primate groups is maintained through time by social grooming (see Dunbar 1988). Social grooming is used both to establish and to service those friendships and coalitions that give primate groups their unique structure. As might be anticipated, the amount of time devoted to social grooming correlates well with group size, notably among the catarrhine primates (Old World monkeys and apes) (Dunbar 1991).
However, the relationship between group size and time devoted to grooming appears to be a consequence of the intensity with which a small number of key "friendships" (the primary network) is serviced rather than to the total number of individuals in the group (Dunbar 1991; Kudo et al, in preparation). These primary networks function as coalitions whose primary purpose is to buffer their members against harassment by the other members of the group. The larger the group, the more harassment and stress an individual faces (see for example Dunbar 1988) and the more important those coalitions are. It seems that a coalition's effectiveness (in the sense of its members' willingness to come to each other's aid) is directly related to the amount of time its members spend grooming each other (see Cheney & Seyfarth 1984, Dunbar 1984). Hence, the larger the group, the more time individuals devote to grooming with the members of their coalitionary clique.
The mean size of the primary network is, however, related to the mean group size for the species. This suggests that groups are built up by welding together sets of smaller primary networks (see also Cheney 1992) and that the total size of the group is ultimately limited not by the number of networks that can be welded together but rather by the size of the networks themselves.
In this paper, I ask what implications these two sets of results have for modern humans (Homo sapiens sapiens). If we extrapolate from the nonhuman primate regression, what group size would we predict for anatomically modern humans, given our current neocortex size? I then ask whether there are any observed human group sizes that correspond to this predicted value. Since the relationships that maintain group cohesion among nonhuman primates are serviced by social grooming, I use the regression equation for primates to determine how much time humans would have to spend grooming each other if they were to maintain group cohesion in this way for groups of the size predicted from neocortex size. Finally, I ask what implications this might have had for the evolution of language.
2. Methods
A number of different measures have been used in comparative analyses to provide unbiased estimates of relative differences in brain size. These have included the Extra Cortical Neurons Index (the ratio of the observed number of cortical neurons over and above those required for somatic maintenance, as estimated from body size, brain size and neural density: Jerison 1973), the cerebral Progression Index (the ratio of observed brain or neocortical volume to that predicted for a basal Insectivore of the same body size: Stephan 1972), the Encephalisation Quotient (the residual of brain volume, or neocortex volume, regressed against body weight: Jerison 1973, Clutton-Brock & Harvey 1980, Sawaguchi & Kudo 1990) and the Neocortex Ratio (neocortex volume divided by the volume of the rest of the brain or the volume of the hindbrain: Dunbar 1992a).
In examining the relationship between neocortex size and group size in nonhuman primates, I found that all these measures are reasonable predictors of group size. However, Neocortex Ratio (measured against the rest of the brain excluding the neocortex) gives much the best fit, accounting for 76% of the variance in mean group size among 36 genera of Prosimian and Anthropoid primates (using data on neocortex volume provided by Stephan et al 1981) (see Dunbar 1992a).
This analysis was based on the mean group size observed for a given genus rather than the maximum group size. The main justification for using the mean group size in these analyses lies in the nature of primate social groups. In contrast to the relatively simple aggregations typical of many birds and herbivores, primate groups are highly structured with individual animals embedded in a complex set of social and kinship networks (see Dunbar 1988, 1989a). Whereas bird flocks can shed individuals through trickle migration as soon as they exceed their optimal size, primate groups cannot: they have to wait until the group is large enough to permit it to fission into two or more daughter groups of a minimum size necessary to ensure the safety and survival of their members. This means that primate groups tend to oscillate in size over quite a wide range around the optimal value. At the point of fission (by definition, their maximum observed size), groups tend to be unstable and close to social disintegration: this, of course, is why they undergo fission at that point. Hence, maximum group size is likely to represent the point of complete social collapse rather than the maximum size of group that the animals can maintain as a cohesive social unit. Consequently, mean group size is likely to be a better estimate of the limiting group size for a species than the maximum ever observed in any population (for further discussion, see Dunbar 1992a).
3. Results
3.1. Group Size in Modern Humans
The best-fit reduced major axis regression equation between neocortex ratio and mean group size for the sample of 36 primate genera shown in Fig.1 was found to be:
log(N) = 0.093 + 3.389 log(CR) (1) (r2=0.764, t34=10.35, p<0.001),>
With a neocortex volume of 1006.5 cc and a total brain volume of 1251.8 cc (Stephan et al 1981), the neocortex ratio for humans is CR=4.1. This is about 50% larger than the maximum value for any other primate species (see Dunbar 1992a). Strictly speaking, of course, extrapolation from regression equations beyond the range of the X-variable values on which they are based is frowned on. However, we can justify doing so in this case on the grounds that our concern at this stage is exploratory rather than explanatory. We do so, therefore, in the knowledge that the confidence limits around any predictions are likely to be wide.
Equation (1) yields a predicted group size for humans of 147.8. Because the equation is log-transformed and we are extrapolating well beyond the range of neocortex ratios on which it is based, the 95% confidence limits around this prediction (from formulae given by Rayner 1985) are moderately wide (100.2- 231.1). Equations based on alternative indices of neocortex size (see Dunbar 1992a, Table 2) yield predicted group sizes that range from 107.6 (EQ residual of neocortex volume regressed against body weight) to 189.1 (Jerison's Extra Neocortical Neurons index) and 248.6 (absolute neocortex volume), all of which are within (or close to) the 95% confidence limits on the neocortex ratio equation.
In trying to test this prediction, we encounter two problems. One is deciding just what counts as the "natural" condition for H. s. sapiens; the other is the problem of defining the appropriate level of grouping for human societies living under these conditions.
It is generally accepted that human cultural evolution has proceeded at a very much faster pace than our anatomical evolution during the past few millenia. Given that our brain size has its origins in the later stages of human evolution some 250,000 years ago (Martin 1983, Aiello & Dean 1990), we may assume that our current brain size reflects the kinds of groups then prevalent and not those now found among technologically advanced cultures. The closest we can get to this is to examine those modern humans whose way of life is thought to be most similar to that of our late Pleistocene ancestors. These are generally presumed to be the hunter-gatherers (Service 1962, Sahlins 1972).
Given that hunter-gatherers are the only appropriate source of information, we then face the problem of deciding what constitutes the appropriate level of grouping within hunter- gatherer societies. There has, however, been considerable debate within anthropology as to the precise structure of these societies (see Service 1962, Birdsell 1970, Williams 1974, Morris 1982, Lee 1982). Irrespective of how this debate is eventually resolved, it is nonetheless clear that most hunter-gatherers live in complexly structured social universes that involve several different levels of grouping.
Thus, the !Kung San of southern Africa live in camps whose composition can change from day to day, but whose membership is mostly drawn from a distinct set of individuals whose foraging area is based on a number of more or less permanent waterholes; several of these "regional groups" make up a much larger tribal grouping typically based on a common dialect and occupancy of a given geographical area (see Lee 1982). The temporary living groups are drawn together into their larger regional groupings for up to three months each year when they congregate at traditional dry season camps based on what is often the only permanent waterhole in the region.
Lee (1982) refers to this as a concentration/dispersal social system and suggests that its origins lie in the unpredictable nature of food and water sources in typical Bushman habitats. He also argues that this form of flexible social system is typical of most (if not all) modern hunter-gatherers: rather similar patterns of social organisation have been documented, for example, among the Australian aboriginals (Meggitt 1965, Strehlow 1947), various Eskimo societies (Spencer 1959, Damas 1968), many of the North American Indian tribes (Helm 1968, Leacock 1969, Steward 1938, Drucker 1955) and among the Congo pygmies (Turnbull 1968, Hewlett 1988).
Given this complexity, any attempt to determine the "true" group size in hunter-gatherers would almost certainly be challenged by anthropologists on innumerable ethnographic grounds. In addition, two other more general objections might be raised. One is that most surviving hunter-gatherers occupy marginal habitats, and this may well influence both the size and the structure of their social systems (as is known to be the case with baboons, for example: Dunbar 1992a, in press). The second is that most living hunter-gatherer societies have been seriously disrupted, either directly or indirectly, by contact with modern colonial cultures.
In view of these caveats, and rather than get involved in the kind of fruitless argument about definitions that has so often clouded the literature in this area, I will proceed more cautiously and simply ask whether we find any groups at all that are consistently of the size predicted for modern humans by equation (1). Given the definition of grouping elaborated in the Introduction, the central issue is not whether a particular form of grouping occurs in every social system but whether a particular size of grouping does so.
Unfortunately, ethnographers have not often regarded censusses as an important feature of their investigations: although most studies allude to groupings of different kinds and often describe the structural relationships between them in great detail, they seldom provide quantitative data on the sizes of these groupings. Table 1 summarises all the data I have been able to find in the ethnographic literature for a number of historical and contemporary hunter-gatherer and swidden horticulturalist societies. I have included swidden horticulturalists since these may reasonably be considered to be settled hunter-gatherers (see Johnson & Earle 1987).
The data in Table 1 suggest that group sizes fall into three quite distinct size classes: small living groups of 30-50 individuals (commonly measured as overnight camps, but often referred to as bands in some of the hunter-gatherer literature), a large population unit (the tribe or in some cases sub-tribe) that typically numbers between 500 and 2500 individuals and an intermediate level of grouping (either a more permanent village or a culturally defined clan or lineage group) that typically contains 100-200 people. In a few cases (e.g. the Mae Enga and the Kaluli of New Guinea), more than three grouping layers were identified by the ethnographer. Most such groupings are, however, organised in a hierarchically inclusive fashion and I have therefore identified the groupings that are closest to the senses defined above.
Plotting these values on a graph produces what appears to be a clear trimodal distribution of group sizes with no overlap between grouping levels (Fig. 2). The average size of the smallest and largest grouping levels (means of 37.7 and 1154.7, respectively) correspond quite closely to the figures for bands (30-50) and tribal groups (1000-2000) that are widely quoted in the anthropological literature (e.g. Steward 1955, Service 1962). The level of grouping that appears to lie between these two has, however, been given little more than passing attention (even though the social significance of such groupings as clans have been discussed extensively). This is reflected in the large number of ? entries in Table 1, indicating that the ethnographer discussed such a grouping but gave no indication of its actual size.
The average size of the intermediate level groups for those societies for which accurate census data are available is 148.4 (range 90-221.5, N=9). If all the available data are considered (taking median values in cases where only ranges are given), the mean is 134.8 (N=15); if only nomadic hunter-gatherers are considered, the mean is 156.4 (N=4). None of these estimates differs significantly from the predicted value (z< +0.431, P>0.667 2-tailed). Indeed, with one exception (the Mae Enga of New Guinea), all the values given in Table 1 lie within the 95% confidence limits of the predicted value (and even the exception is only just outside the lower 95% confidence limit). More importantly, in no case does the mean size of any temporary camp or tribal grouping (i.e. the smaller and larger grouping types) lie within the 95% confidence limits on the predicted group size. Indeed, the mean values for the band and tribal level groupings are significantly different from the predicted value (z=6.401 and z=9.631, respectively, P<<0.0001).>
Note that the coefficient of variation for the intermediate level grouping is considerably smaller than those for either of the other two groupings (Table 1). This suggests that the constraints on the former are greater than those on the latter, as might be expected if the former is subject to an intrinsic (e.g. cognitive) constraint whereas the latter are more often determined by extrinsic environmental factors. The size of hunter-gatherer "bands" (or night camps), for example, is known to be particularly unstable and to be seasonally adjusted to the group's resource base (Turnbull 1968, Lee 1982, Johnson & Earle 1987). In contrast, the greater variability in the size of the tribal level groupings almost certainly reflects the impact of contact with modern (especially European) cultures and their attendant diseases; in many cases, these have drastically reduced the size of indigenous tribes.
It is important to note that the intermediate level groupings do not always have an obvious physical manifestation. Whereas overnight camps can readily be identified as demographic units in time and space and the tribal groupings can be identified either by linguistic homogeneity or geographical location (and often both), the intermediate level groupings are often defined more in terms of ritual functions: they may gather together once a year to enact rituals of special significance to the group (such as initiation rites), but for much of the time the members can be dispersed over a wide geographical area and, in some cases, may even live with members of other clan groupings. Nonetheless, what seems to characterise this level of grouping is that it constitutes a subset of the population that interacts on a sufficiently regular basis to have strong bonds based on direct personal knowledge. My reading of the ethnographies suggests that knowledge of individuals outside this grouping is generally less secure and based more on gross categories (a "Them" and "Us" basis as opposed to identifying individuals by name). More importantly, perhaps, in the case of New Guinea horticulturalists at least, the intermediate level grouping seems to provide an outer network of individuals who can be called on for coalitionary support during raids or the threat of attack by other groups (see Meggitt 1965b, Hallpike 1977). Thus, this intermediate level of grouping in human societies seems to correspond rather precisely in both size and social function to what we would expect on the basis of the nonhuman primate data.
It is of interest to note that estimates of the size of Neolithic villages in Mesopotamia are of about the same magnitude. Oates (1977), for example, gives a figure of 150-200, based on the fact that 20-25 dwellings seems to be the typical size of a number of village sites dated to around 6500-5500 BC.
In fact, it turns out that figures in the region of 150 occur frequently among a wide range of contemporary human societies. Thus, the mean size of the 51 communities (or Bruderhoefe) in the Schmedenleut section of the Hutterites (a fundamentalist group who live and farm communally in South Dakota and Manitoba) is 106.9 individuals (Mange & Mange 1980). According to Hardin (1988), the Hutterites regard 150 individuals as the limiting size for their farming communities: once a community reaches this size, steps are taken to split it into two daughter communities. Bryant (1981) provides another example from an East Tennessee rural mountain community (all of whom claim to be related to each other and regard themselves as a single social group): the total number of living members was 197 when the community was censussed at the end of the 1970s. Even academic communities appear to abide by this rule. Price & Beaver (1966), for example, found that research specialities in the sciences tend to consist of up to 200 individuals, but rarely more. Becher (1989) sampled network sizes (defined as the number of individuals whose work you pay attention to) in 13 academic sub- disciplines drawn from both the sciences and the humanities and concluded that the typical size of the outer circle of professional associates that defines a sub-discipline is about 200 (with a range between 100-400). It seems that disciplines tend to fragment with time as their numerical size (and, of course, literature) grows.
In addition, it turns out that most organised (i.e. professional) armies have a basic unit of about 150 men (Table 3). This was as true of the Roman Army (both before and after the reforms of 104BC) as of modern armies since the sixteenth century. In the Roman Army of the classical period (350-100 BC), the basic unit was the maniple (or "double-century") which normally consisted of 120-130 men; following the reforms instituted by Marius in 104BC, the army was re-organised into legions, each of which contained a number of semi-independent centuries of 100 men each (Haverfield 1955, Montross 1975). The smallest independent unit in modern armies (the company) invariably contains 100-200 men (normallly three or four rifle platoons of 30-40 men each, plus a headquarters unit, sometimes with an additional heavy weapons unit) (Table 3). Although its origins date back to the German mercenary Landsknechts groups of the sixteenth century, the modern company really derives from the military reforms of the Swedish king Gustavus Adolphus in the 1620s. Despite subsequent increases in size to accomodate new developments in weaponry and tactics, the company in all modern armies has remained within the 95% confident limits of the predicted size for human groups. The mean size of 179.6 for the twentieth century armies listed in Table 3 does not differ significantly from the 147.8 predicted by equation (1) (z=0.913, P=0.361 2-tailed).
This fact has particular significance in the context of the present argument. Military units have to function very efficiently in coordinating men's behaviour on the battlefield: the price of failing to do so is extremely high and military commanders cannot afford to miscalculate. Given that the fighting power of a unit is a function of its size, we might expect there to be considerable selection pressure in favour of units that are as large as possible. That the smallest independent unit should turn out to have a maximum size of about 200 even in modern armies (where technology presumably facilitates the coordination of planning) suggests that this upper limit is set by the number of individuals who can work effectively together as a coordinated team. Military planners have presumably arrived at this figure as a result of trial and error over the centuries.
In the context of the present analysis, the reason given by the Hutterites for limiting their communities to 150 is particularly illuminating. They explicitly state that when the number of individuals is much larger than this, it becomes difficult to control their behaviour by means of peer pressure alone (Hardin 1988). Rather than create a police force, they prefer to split the community. Forge (1972) came to a rather similar conclusion on the basis of an analysis of settlement size and structure among contemporary New Guinea "neolithic" cultivators. He argued that the figure 150 was a key threshold in community size in these societies. When communities exceed this size, he suggested, basic relationships of kinship and affinity were insufficient to maintain social cohesion; stability could then be maintained only if formal structures developed which defined specific roles within society. In other words, large communities were invariably hierarchically structured in some way, whereas small communities were not.
Similarly, in an analysis of data from 30 societies ranging from hunter-gatherers to large-scale agriculturalists, Naroll (1956) demonstrated that there was a simple power relationship between the maximum settlement size observed in a given society and both the number of occupational specialities and the number of organisational structures recorded for it. His analyses suggest that there is a critical threshold at a maximum settlement size of 500 beyond which social cohesion can only be maintained if there is an appropriate number of authoritarian officials. Bearing in mind that Naroll's threshold is expressed as the maximum observed settlement size, it seems likely that the equivalent mean settlement size will not be too far from the value of 150 suggested by the above analyses.
Other evidence suggests that 150 may be a functional limit on interacting groups even in contemporary western industrial societies. Much of the sociometric research on industrial and other comparable organisations, for example, has demonstrated that there is a marked negative effect of group size on both group cohesion and job satisfaction (as indicated by absenteeism and turnover in posts) within the size range under consideration (i.e. 50-500 individuals: see, for example, Indik 1965, Porter & Lawler 1965, Silverman 1970). Indeed, an informal rule in business organisation identifies 150 as the critical limit for the effective coordination of tasks and information-flow through direct person-to-person links: companies larger than this cannot function effectively without sub-structuring to define channels of communication and responsibility (J.-M. Delwart, pers. commun.). Terrien & Mills (1955), for example, found that the larger the organisation, the greater the number of control officials that is needed to ensure its smooth functioning.
Other studies have suggested that there is an upper limit on the number of social contacts that can be regularly maintained within a group. Coleman (1964) presented data on friendships among print shop workers which suggest that the likelihood of having friends within the workplace reaches an asymptote at a shop size of 90-150 individuals. (The small size of the sample for large groups makes it difficult to identify the precise point at which "saturation" is reached.) Coleman explicitly argued that this was a consequence of the fact that there is a limit to the number of individuals within a shop that any one person can come into contact with. Moreover, his results also seemed to suggest that the large number of regular interactants that an individual can expect to have within a large work group limits the number of additional friendships that can be made outside the workplace.
Most studies of social networks in modern urban societies have tended to concentrate on specific sub-sets (e.g. "support networks") within the wider network of "friends and acquaintances" (see Mitchell 1969, Milardo 1988). One exception to this has been the study by Killworth et al (1984) who used a "reversed small world" protocol to determine the total network size (i.e. the total number of individuals that are known by name with whom a respondent has a degree of personal contact). Forty subjects were each given a dossier containing 500 fictious (but realistic) target individuals living in different parts of the world and asked to name an individual among their own acquaintances who (either directly or via a chain of acquaintances of their own) would be able to pass a message to each of the targets. The number of different acquaintances listed was assumed to be an index of the subject's total social network. The mean number of acquaintances selected was 134 (though the variance around this figure was considerable). Since the number of nominated acquaintances seems to increase more slowly as the number of targets increases, Killworth et al (1984) suggested that the asymptotic network size could be determined by extrapolation from the rate at which the curve of nominated acquaintances increases with increasing numbers of targets. They calculated this value to be about 250. Though just outside the 95% confidence limits on the predicted value (z=2.29, P=0.022 2- tailed), this latter estimate is not so far outside the range of likely values as to be seriously worrying. For one thing, the difference between the mean and asymptotic values may well reflect the difference between the functional norm (i.e. the number of personal friends that an individual has) and the maximum network size when more peripheral acquaintances are included. More research in this area is clearly needed to clarify this.
3.2. Grooming and the Evolution of Language
Given that primate groups are held together by social grooming, time budget constraints on group size become an important consideration (Dunbar 1992b). Even if a species has the cognitive capacity to manage all the relationships involved in large groups, there may be circumstances under which the animals simply do not have the time available to devote to servicing those relationships through social grooming. Relationships that are not serviced in this way will cease to function effectively; as a result, the group will tend to disperse and the population will settle at a new lower equilibrium group size (Dunbar 1992b).
A comparative analysis of the determinants of time spent grooming by primates has demonstrated that grooming time is a linear function of group size, at least within the catarrhine primates (Dunbar 1991). The distribution of the data suggests that grooming does not necessarily function in such a way that each individual grooms with every other group member: rather, as noted earlier (p.000), it suggests that the intensity of grooming with a small number of "special friends" (or coalition partners) increases in proportion to increasing group size. Irrespective of precisely how grooming functions to integrate large primate groups, we can use the relationship between group size and grooming time to predict the grooming time required to maintain cohesion in groups of the size predicted for modern humans.
Since our main concern is with how time spent grooming functions to maintain group cohesion, I have considered only those catarrhine species which do not have fission-fusion social systems. For the 22 species listed in Dunbar (1991, Table 1) that are described as living in stable cohesive groups, the reduced major axis regression equation is:
G = -0.772 + 0.287 N (2) where G is the percentage of time devoted to social grooming during the day (r2=0.589, t20=5.36, P<0.001:>
(Alternative forms for equation [2] using least-squares regression and/or the full Catarrhine data-set yield equations that are very similar in form, but whose coefficients vary somewhat. Although this affects the absolute values for the grooming time requirement, it does not affect their relative values; hence, the argument itself is unaffected. Equation [2] seems to give a generally better fit to the primate data; in particular, it yields a more accurate prediction of the amount of time devoted to social grooming in the very large groups typical of the gelada. I have preferred to use it here mainly for this reason.)
The group size predicted for modern humans by equation (1) would require as much as 42% of the total time budget to be devoted to social grooming. (The 95% confidence limits on predicted group size would yield grooming times that range from 28% to 66%.) This is more than double that observed in any population of nonhuman primates. Bearing in mind that this figure refers to the average group size, and that many groups will be substantially larger than this, the implications for human time budgets are clearly catastrophic. A group of 200, for instance, would have to devote 56.6% of its day to social grooming. For any organism that also has to earn a living in the real world, this would place a significant strain on its ability to balance its time budget. This problem would clearly be compounded if thermoregulatory considerations forced individuals to take time out to rest in shade during the hottest parts of the day: among baboons at least, temperature-driven resting appears to be incompatible with social interaction (Dunbar 1992b).
To place this in perspective in relation to relative neocortex size in the hominoids, I have calculated the equivalent figures for predicted group size and grooming time for all the genera of hominoids (Table 3). (The fact that only the chimpanzees live in groups of the size predicted by equation [1] is not of significance in the present context: this point is discussed in more detail in Dunbar [1992a].) The question I want to ask here is whether the neocortex size of non-human hominoids is large enough to yield group sizes that would lead to a time- budgetting crisis if the group's relationships had to be serviced by social grooming alone. Table 3 suggests that, although group size increases steadily through the hominoids, in no case is the grooming time requirement predicted by equation (2) excessive by the standards of other catarrhine primates. The figure of around 15% social time predicted for orang utans and chimpanzees compares very favourably with the values actually observed among baboons and macaques (see Dunbar 1991). Although larger bodied apes would need to spend a rather higher proportion of their day foraging than smaller-bodied baboons, the predicted grooming time requirement is not such as to suggest that it would place excessive pressure on their time budgets. Data summarised by Wrangham (1986) indicate that the various chimpanzee populations spend 25-43% of their time in non-foraging activities (mainly resting and social interaction). None of these populations would be forced to forgo any foraging time were they to spend as much as 20% of their time in social grooming.
The situation for modern humans is clearly very different and such high grooming time requirements simply could not be met. In baboons, it has been shown that when the actual amount of time devoted to social interaction is less than that predicted for a group of the observed size, the group tends to fragment easily during foraging and often subsequently undergoes fission (Dunbar 1992b). Faced with this problem, there are, in principle, only two solutions: either reduce group size to the point where the amount of grooming time is manageable or use the time that is available for social bonding in a more efficient way.
Given that minimum group sizes are ecologically imposed (see Dunbar 1988), there may be little that a particular species can do to manipulate its group size in a particular habitat. The only option will thus be a more efficient use of the time available for social bonding. In this context, the main problem with grooming as a bonding mechanism is that it is highly inflexible: it is all but impossible to do anything else while grooming or being groomed. In addition, grooming is an essentially dyadic activity: only one other individual can be groomed at a time.
Modern humans do, however, possess a form of social communication that overcomes both of these limitations very effectively: not only can speech be combined with almost every other activity (we can forage and talk at the same time), but it can also be used to address several different individuals simultaneously. Thus, language introduces major savings by allowing an individual to do two different things at once. My suggestion, then, is that language evolved as a "cheap" form of social grooming, so enabling the ancestral humans to maintain the cohesion of the unusually large groups demanded by the particular conditions they faced at the time.
3.3. Language as a Bonding Mechanism
That language (and hence speech) might have evolved as a consequence of the need to increase group size raises the question of just how it functions as a bonding mechanism. Conventionally, language has always been interpreted in terms of the exchange of information, and this has usually been understood as being the exchange of information about the environment (e.g. the location of prey, the coordination of behaviour during the hunt). However, the social intelligence hypothesis for the evolution of large brain size in primates (see Byrne & Whiten 1988) implies that the acquisition and manipulation of social knowledge is the primary consideration. The fact that language can be interpreted as fulfilling the same role as social grooming suggests that, rather than being the selective factor driving brain evolution, ecologically-related information-exchange might be a subsequent development that capitalised on a window of opportunity created by the availability of a computer with a substantial information-processing capacity.
How might language function as a mechanism for social bonding? There would appear to be at least two possibilities. One is by allowing individuals to spend time with their preferred social partners, thereby enabling them to acquire information about each other's behaviour by direct observation. This appears to be one way in which social grooming itself might work (Dunbar 1988). That the intellectual content of human conversations is often trivial (and, indeed, many conversations are highly formulaic and ritualised) lends some support to this argument. The second possibility is that language permits the acquisition of information about third party social relationships, thereby enabling an individual to acquire knowledge of the behavioural characteristics of other group members without actually having to observe them in action. (I am grateful to R.W.Byrne for pointing this out to me.) This would have the effect of considerably widening an individual's sphere of social knowledge relative to what would be possible from direct personal observation. This suggestion meshes well with the social intelligence hypothesis, and is given some support by the extent to which humans seem to be fascinated by gossip about other people's behaviour.
It is rather difficult to test unequivocally between these two alternatives. In any case, it is not obvious that they are necessarily mutually exclusive. However, it is clear that, if the second explanation is true, gossip about third party social relationships must constitute an important component of human conversations. Table 4 summarises data on the content of conversations in a university refectory. Approximately 38% of conversation content was devoted to personal relationships (either of those present or of third parties) and a further 24% involved discussion of personal experiences of a more general kind, both topics being clearly related to social knowledge. Considering the potential importance of academic and other intellectual topics of conversation in a university environment, these are remarkably high values. The acquisition and exchange of information about social relationships is clearly a fundamental part of human conversation. I suggest that it implies that this was the function for which it evolved.
3.4. Efficiency of Language as a Bonding Mechanism
If language evolved purely as a form of vocal grooming in order to facilitate the evolution of larger social groups, its design properties should be of about the right efficiency relative to grooming to allow an increase in group size from the largest observed in nonhuman primates to those predicted for modern humans. By "efficiency" here, I mean the number of interactants that can be simultaneously reached during a social interaction. In social grooming, this is necessarily one, because grooming can only be a one-to-one interaction. Language would thus need to allow proportionately as many individuals to be interacted with at the same time as is necessary to raise the size of nonhuman primate groups up to that predicted for modern humans.
The observed mean group size for chimpanzees (presumably the closest approximation to the ancestral condition for the hominid lineage) is 53.5 (Dunbar 1992a). Since the predicted size for human groups is 147.8, this implies that language (the human bonding mechanism) ought to be 147.8/53.5=2.76 times as efficient as social grooming (the nonhuman primate bonding mechanism). (The figure would be 2.27 if we used the neocortex-predicted group size of 62.5 given in Table 3 for chimpanzees.) In terms of the argument outlined here, this means that a speaker should be able to interact with 2.8 times as many other individuals as a groomer can. Since the number of grooming partners is necessarily limited to one, this means that the limit on the number of listeners should be about 2.8. In other words, human conversation group sizes should be limited to about 3.8 in size (one speaker plus 2.8 listeners).
Table 5 summarises data on small group sizes from a number of studies. Cohen (1971), for example, censussed the distribution of group sizes from the reservations book for Novak's Restaurant in Brookline (Mass.) over a 98 day period in 1968. Although the distribution was double-peaked (with near equal modes at 2 and 4, as might be expected), the mean size of 3070 groups was 3.8. (If groups of less than three people are excluded on the grounds that they have other concerns that social interaction, then the mean of 2020 groups is 4.8, but the modal group size is just 4 with a highly skewed distribution.) James (1952) collated information on the size of committees in a number of national and local government institutions in the USA, as well as four business corporations: mean size varied from 4.7 to 7.8 with distributions that were highly skewed towards the low end. In a study of freely forming groups in Portland (Oregon), James (1953) found a mean group size of 2.7 (solitary individuals excluded) on a public beach area. Group sizes were slightly smaller, but comparable, in a variety of other social contexts (shopping precincts, open streets, bus depots, school play grounds).
The most direct evidence, however, comes from a study of conversation group sizes carried out in a university refectory. Dunbar & Duncan (submitted) censussed conversational cliques that formed freely within interacting groups that varied in size from 2-10 individuals. They found that the average number of people directly involved in a conversation (as speaker or attentive listener) reached an asymptotic value of about 3.4 (one speaker plus 2.4 listeners) and that groups tended to partition into new conversational cliques at multiples of about four individuals (Fig. 4).
It turns out that there is, in fact, a psycho-physical limit on the size of conversation groups. Due to the rate at which speech attenuates with the distance between speaker and hearer under normal ambient noise levels, there is a physical limit on the number of individuals that can effectively take part in a conversation. Sommer (1961), for example, found that a nose-to- nose distance of 1.7m was the upper limit for comfortable conversation in dyadic groups; this would yield a maximum conversation group size of five individuals with a shoulder-to- shoulder spacing of 0.5m between adjacent individuals standing around the circumference of a circle.
Theoretical and empirical studies of signal-attenuation rates suggest that, as the circle of interactees expands with increasing group size, the distances between speaker and listeners across the circle rapidly become too large for conversations to be heard (Beranek 1954, Webster 1965, Cohen 1971). In addition, Webster (1965) found that a doubling of the distance between speaker and hearer reduces by about 6 Db the level of background noise that can be tolerated for any given criterion of speech recognition accuracy, with the reduction being proportionately greater for those with lighter voices (e.g. women). Cohen's (1971) analyses of these results suggested that at background noise levels typical of both offices and city streets, conversational groups will be limited to a maximum of seven individuals if they maintain a spacing distance of about 0.5m apart even when they speak in a raised voice; groups of five would be the limit with normal voice levels.
Although background noise levels in natural environments are unlikely to approach those found on busy city streets, comparably high noise levels are commonly found in large interacting human groups. Legget & Northwood (1960) measured maximum noise levels at cocktail parties of 120-640 people (including a coffee party for librarians!): they found noise levels that were typically in the region 80-85 Db in the mature stages of these parties. This is considerably in excess of the noise levels recorded in city streets and only just below the level sufficient to induce hearing impairment. At such levels, speech recognition is close to zero, conversation becomes impossible and maximum group size approaches one (see Cohen 1971, Fig. 7.1). Such noise levels may not be untypical of the periodic ritual social gatherings of primitive societies at which relationships are renewed and social gossip about third parties exchanged.
In summary, these results suggest that conversation does meet the requirements of a more efficient bonding mechanism, and that it does so at about the level relative to social grooming that is required to facilitate an increase in group size from those observed in nonhuman primates. Moreover, the psycho- physical properties of human speech provide some evidence to suggest that they are correlated with these demographic characteristics of human groups.
4. Discussion
The essence of my argument has been that there is a cognitive limit to the number of individuals with whom any one person can maintain stable relationships, that this limit is a direct function of relative neocortex size, and that this in turn limits group size. The predicted group size for humans is relatively large (compared to those for nonhuman primates), and is close to observed sizes of certain rather distinctive types of groups found in contemporary and historical human societies. These groups are invariably ones that depend on extensive personal knowledge based on face-to-face interaction for their stability and coherence through time. I argued that the need to increase group size at some point during the course of human evolution precipitated the evolution of language because a more efficient process was required for servicing these relationships than was possible with the conventional nonhuman primate bonding mechanism (namely, social grooming). These arguments appear to mesh well with the social intelligence hypothesis for the evolution of brain size and cognitive skills in primates.
Three points should be noted. One is that there is no obligation on particular human societies to live in groups of the predicted size: the suggestion here is simply that there is an upper limit on the size of groups that can be maintained by direct personal contact. This limit reflects demands made on the ancestral human populations at some point in their past history. Once neocortex size has evolved, other factors may of course dictate the need for smaller groups. Precisely this effect seems to occur in gibbons and orang utans: in both cases, neocortex size predicts groups substantially larger than those observed for these species, but ecological factors apparently dictate smaller groups (Wrangham 1979). Thus, the observation that Australian Aboriginal tribes living in the central desert regions lack the larger clan-like groups does not necessarily disprove the hypothesis. The marginal habitats occupied by these peoples seems to dictate a foraging strategy based on small dispersed groups living in very large territories; this almost certainly creates communication problems that preclude the formation of larger social networks. The hypothesis would be invalidated, however, if there was no evidence for clan-like groupings in more productive environments.
(It is, incidentally, worth observing that we might expect the upper limit on group size to depend on the degree of social dispersal. In dispersed societies, individuals will meet less often and will thus be less familiar with each, so group sizes should be smaller in consequence; in spatially concentrated societies, on the other hand, individuals will see each other more often and group sizes should be proportionately larger.)
The second point is that the limit imposed by neocortical processing capacity is simply on the number of individuals with whom a stable inter-personal relationship can be maintained. This in no sense commits us to any particular way of structuring those groups (e.g. via kinship). Although the layers of grouping listed in Table 1 are often based on biological relatedness (involving the successive fission of what are usually termed segmentary lineages: see for example Meggitt 1965b), there is no requirement that groups necessarily have to be organised on genetic principles. Kinship is one dimension of primate societies that is relevant to individuals' decisions about whom to group with, and it often provides a convenient means for structuring a hierarchically inclusive pattern of grouping (see Dunbar 1988). However, even among nonhuman primates, it is not the only basis on which individuals choose whom to form groups and/or alliances with (see Cheney 1983). Primate groups are, strictly speaking, coalitions based on common interest and any number of biological, economic and social dimensions besides kinship may be relevant in individual cases (see, for example, de Waal & Luttrell 1986).
Finally, it should be noted that this explanation clearly stands in direct contrast to the conventional wisdom that language developed in the context of hunting to enable early hominids to communicate about the location of possible prey and to plan coordinated hunting expeditions. Indeed, the explanation for the increase in brain size within the hominid lineage on which my argument is based itself stands in contradiction to the conventional wisdom that these large brains evolved to enable humans to hunt and/or manufacture tools. Others (e.g. Wynn 1988; see also Blumenberg 1983) have already pointed out that the evolution of large brain size within the hominid lineage does not correlate well with the archaeological record for changes in tool construction. The markedly improved tool designs of the Upper Palaeolithic can thus be better interpreted as a consequence rather than a cause of enlarged brain size.
This analysis raises a number of additional questions. (1) At what point during the process of human evolution from the common pongid ancestor did such unusually large groups (and hence language) evolve? (2) How is it that, despite these apparent cognitive constraints on group size, modern human societies are nonetheless able to form super-large groups (e.g. nation states)? (3) To what extent is language a uniquely novel solution confined to the hominid lineage?
The fossil evidence (see Aiello & Dean 1990) suggests that brain size increased exponentially through time within the hominid lineage, being well within the pongid range for the Australopithecus species and not showing a marked increase until the appearance of Homo sapiens. This would tend to suggest that neocortex sizes are unlikely to have been sufficiently large to push the grooming time requirement through the critical threshold at about 25-30% of the time budget until quite late in hominid evolution. Application of equations (1) and (2) to all the fossil hominids for which cranial capacity estimates are available identifies the appearance of archaic Homo sapiens at about 250,000 years BP as the point at which language most likely evolved (Aiello & Dunbar, submitted). (It turns out that neocortex ratio is a simple allometric function of cranial capacity in all primates, including humans, with a very high coefficient of determination, thus allowing us to determine group sizes even for extinct species.) Language would thus have been a rather late evolutionary development. Just why early humans should have found it necessary to evolve such large groups remains uncertain, however, and there is little that can usefully be said to clarify this point at present (for further discussion, see Aiello & Dunbar, submitted).
(Let me forestall at least one line of criticism at this point by observing that the fact that we cannot identify a functional explanation to account for the evolution of a trait does not invalidate the fact that such a trait has evolved: it merely signals our limited knowledge. Humans clearly have larger group sizes than nonhuman primates, and groups of that size cannot have appeared by magic for no good reason. Whether we can ever answer that question will ultimately depend on whether we can extract the relevant information from the fossil record. It will also, however, depend on our developing theories of sufficient complexity to allow us to understand the interactions between the various components within what is inevitably a complex socio-ecological system (Tooby & DeVore 1987, Dunbar 1989b).)
The second issue concerns the fact that contemporary human societies are able to maintain very large groupings indeed (in the order of several hundred million individuals in a modern nation state). Two observations are worth making here. One is that the structure of these super-large groupings is not particularly stable through time, as has repeatedly been demonstrated in history by the eventual collapse of most large empires. The other is that language has two unusual properties that make it possible to form groups that are substantially larger than the 150-200 predicted by neocortex size: it allows us (1) to categorise individuals into types and (2) to instruct other individuals as to how they should behave towards specific types of individuals within society. Thus, we can specify that individuals identified as a class by a particular badge (for example a clerical collar or a sherrif's badge) should be treated in a certain rather specific way (e.g. with great deference). A naive individual will thus know how to respond appropriately to a member of that class on first meeting even though s/he has never previously encountered that particular individual before. This may be especially important in the case of those types of individuals (e.g. royalty, bishops, etc) that the average citizen does not normally have the opportunity to meet. Subsequent more intimate interactions may, of course, allow the relationship to be fine-tuned in a more appropriate way, but conventional rules of this kind at least make it possible to avoid the initial risk of souring a potential relationship by inappropriate behaviour at the first meeting.
This ability to categorise individuals into types clearly makes it possible to create very much larger groups than is possible by direct interaction. It is only necessary to learn how to behave towards a general type of individual, rather than having to learn the nature of each individual relationship. By structuring relationships hierarchically in this way, social groups of very substantial size can in principle be built up. The obvious example is, once again, the hierarchical structuring of military units. Notice that, even in this case, members of different groupings are often given distinctive badges or uniforms in order to allow them to be identified easily: this applies not only to categories of individuals who are considered to be "important" (e.g. officers) but also to members of different types of unit who are of equivalent status in the hierarchy (e.g. military policemen, marines, different regiments, etc).
It is significant, however, that larger groupings of this size appear to be very much less cohesive than groups that are smaller than the critical limit. Language seems to be a far from perfect medium for acquiring detailed social knowledge about other individuals: secondhand knowledge, it seems, is a poor substitute for the real thing. Indeed, it is conspicuous that when we do want to establish very intense relationships, we tend to do so through the much more primitive medium of physical contact rather than through language. The kind of "mutual mauling" in which we engage under these circumstances bears a striking resemblance to social grooming in other primates -- and suffers from all its disadvantages. One study of social grooming in a natural human population, for example, found that 92% of all grooming interactions were dyadic (Sugawara 1984). In this context, it is relevant to note that sociometric studies of "sympathy groups" suggest that we are only able to maintain very intense relationships with 10-12 other individuals at any one time (Buys & Larson 1979).
The final issue is the purely phylogenetic one of where language might have evolved from within the natural communication patterns of primates. Can we identify any features of nonhuman primate vocal communication that could function as a natural precursor for human language? The obvious analogy lies in the contact calls used extensively in many species of anthropoid primates to coordinate spacing between individuals of the same group. Although these calls have traditionally been interpreted as a mechanism for maintaining contact during movement (hence their generic name), it has become clear in recent years that there may be more subtle layers of meaning to these calls. Cheney & Seyfarth (1982), for example, found that vervet monkeys use contact calls to comment on events or situations as they occur. They were able to show experimentally that slight differences in the acoustical form of the calls allow the audience to infer a great deal about the event or situation on which the caller is commenting, even in the complete absence of any visual information.
So far, rather little work has been done on the phonetic structure of primate contact calls. The one exception here has been the gelada, whose vocalisations have been analysed in considerable detail by Richman (1976, 1978, 1987). Richman (1976) found that gelada are able to produce sounds that are synonymous with the vowel and consonant sounds (notably fricatives, plosives and nasals, as well as sounds articulated in different parts of the vocal tract such as labials, dentals and velars) that were hitherto thought to be distinctive features of human speech. Furthermore, Richman (1987) has pointed out that the gelada's highly synchronised exchanges of contact calls (see also Richman 1978) possess many of the rhythmic and melodic properties of human speech patterns. The conversational nature of these exchanges led Richman (1987) to suggest that gelada use these musical qualities to designate utterance acts so as to permit hearers to parse the sound sequence into smaller units in just the way that humans do when talking. He specifically related this ability to the social context, in particular the need to resolve the emotional conflicts inherent in many social situations. It is significant that, in the gelada, calling and counter-calling between individuals is closely related to the strength of the relationship between them (see Kawai 1979, Dunbar 1988, p.251).
We do not at present know whether the acoustic features identified by Richman are unique to the gelada. They might well not be. However, the conversational properties of gelada contact calls (in particular their use in highly synchronised bouts, often involving intense emotional overtones) do seem to be unusual. It may therefore be significant that gelada live in the largest naturally occurring groups of any nonhuman primate: the average size of their rather loosely structured bands (a high level grouping within an extended hierarchically organised social system based on a very much smaller stable reproductive unit) is about 110 (see Iwamoto & Dunbar 1983).
Clearly, the gelada have in no sense evolved language in the sense we would use this term of humans, but then neither have they developed the large cohesive groups chararcteristic of our species. However, it may be that the large groups in which this species sometimes gathers forced the evolution of a supplementary vocal mechanism for servicing relationships in a context where they are already at the limit of available grooming time (see Iwamoto & Dunbar 1983, Dunbar 1991). It is worth noting that this much has been achieved without the need to increase neocortex size: indeed, the gelada have a rather small neocortex compared to their baboon cousins (genus Papio) which probably explains the lack of cohesiveness in their larger-scale groups compared to those of the baboons.
This would seem to suggest that many of the basic properties of speech and language were already available in the more advanced nonhuman primates. What was required was their close integration and elaboration, and this may have been dependent on a significant increase in neocortex size in order to provide the necessary computing capacity. I simply suggest that the evolution of this increased capacity arose out of the need to coordinate the large number of inter-personal relationships necessary to maintain the cohesion and stability of larger than normal groups.


I am grateful to a large number of individuals with whom I have discussed the ideas presented in this paper over the past four years, but in particular I thank Leslie Aiello, Dick Byrne and Henry Plotkin for their encouragement and advice.


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