Tribe and Territory

I concluded the previous essay on communication with “Stories develop within the ambit of the tribe and tribalism thus dividing one tribe from another.”  This essay will develop the demographics of social groups that underlies tribalism.  The point of view of this essay is mostly of the human condition ab initio – of hunter gatherer societies prior to the development of demographic compression, sedentism and civilization.

Years ago, when I was still gainfully employed, after dinner I would work in the shop making or fixing something until about 9 PM and then go for a relaxing walk.  In the winter I would avidly sniff the smoke from wood fires and got to thinking that we have a long association with wood fire – probably our oldest and most fundamental technology.  For millennia out of mind the smell of burning wood has been a signal of hearth, home and happiness, and of warmth – we are naked apes without an insulating fur coat.  Fire dries and warms.

But the smoke of burning wood can also signal danger.  Forest fires, yes, but more significant is the smoke of a campfire of another group.  Who are they?  Are they neighboring tribes with which we occasionally exchange mates and gifts?  Why are they there?  Where are they going?  What will they do?  Are they just passing through or do they intend to contest our territory?  What shall we do?  Just thinking of this scene, I can feel the stomach acid churning.  This is our land.  The imminent danger is to our territory, our land that we know so well, roam so widely and freely use.  We cannot lose those resources.  If we lose, we have to move elsewhere, possibly to a lower quality territory or failing that, conquer someone else’s territory or starve.  Wood smoke signals home and friend on the one hand, and fearful danger on the other.

Two words that are intimately tied together in that description of territoriality, our land, form the nucleus of this essay.  Our: we are a social rather than an individual species.  Land: we are perforce territorial.  We are a territorial social species.  We hold land and its resources as a group, not as individuals, and as a group we hold our territory through time beyond the lifespan of any individual.  Our group, our land.  Group implies we and they.  Territory implies ours and yours.  Together they form a linked or nested mosaic dividing the species tribally and the land territorially, each tied to, or over-laid upon, the other.

Biologists, archaeologists, and anthropologists have observed that each species of the primates has a preferred group size.  For humans this ranges from about 25 individuals at the low end to about 150 at the high end in foraging hunter gatherer societies.  The anthropologist, Robin Dunbar, advanced the social brain thesis to explain these observations.  Optimum group size is set by the information bandwidth and processing power of the brain.  Keeping track of individuals, who is doing what to whom, who is dominant and submissive, and who grooms whom.  There are multiple conflict-cooperation axes with fighting at one end, and caring and sharing at the other.  In the center of the group is the mother-child bond, around that, the female-male pair bond, and wrapped over both is the penumbra of tribal care of the young.  There are a lot of social interactions to keep track of.

We are a neurologically and behaviorally complex social, tribal, and territorial species, and mental capacity, effort and time are required to form individuals into a group, to maintain that group, and to function within the group.  Our social brain has limited information bandwidth capacity and processing time.  The upper limit to a group size is set by the intensity, complexity, variability and duration of the permutations and combinations of individual relationships intersecting with that mental capacity.  The net effect is a complex social phase space with a large information content.  Our social brains function best within the upper limit of around 150 individuals.

Our social brain is one layer of the mosaic.  The second layer is our ecological brain.  Foraging hunter gatherer groups have an intimate and detailed knowledge of their territory, of its resources and its dangers.  This too requires information bandwidth and it also generates a high bound on the group size.  A resource rich environment may support a larger group on a smaller territory and vice versa.  Some ecologies, particularly riverine, coastal or estuarial may support small scale sedentary communities, but upland groups will require foraging within larger territories.

Our large brains require an inordinate amount of energy which require more food resources, and that generates the need for a richer or larger territory which requires more information bandwidth, processing power and time to utilize.  Together energy needs, resource and time availability and brain limitations are major factors in setting the upper limit to group size in foraging hunter gatherer societies.

Tribalism and territoriality, we and ours, are the result of these related requirements.  Why can’t we all just get along?  We don’t.  We can’t.  We are tribal and territorial.

That is all well and good, but most humans now live in vast conurbations that are thousands to millions of times greater than the density of foraging hunter gatherer groups.  And we do it rather successfully.  Steven Pinker’s book The Better Angels of Our Nature very carefully makes the case that we are better off for living in these denser groups.  Even those who live on the other side of that fence dividing the socio-economic realities of the favelas of Sao Paulo, Brazil are better off.

I have put forth in an earlier essay the Affluent Savage thesis of Marshall Sahlins, and in this essay, the Better Angels of Our Nature thesis of Steven Pinker.  I can’t have it both ways, or can I?  Buried in that question is a stupendous narrative arc, the evolution of civilization, for which I will appropriate the title of “The Greatest Story Ever Told.”  Between the affluent savage and the citizen lies “the valley of the shadow of death,” to borrow another phrase.

I am going to tell my version of this great story.  The questions underlying this story will be ‘given that our preferred social group size lies in the range of 25 to 150, and we observe that we live in much denser groups, how did this demographic compression happen and what are the consequences?”  And: the sociology of civilization is so much different from that of the hunter gatherers, how did we adapt and how well adapted are we?

These are evolutionary questions.  But to essay an answer, I first have to do some wondering about ‘what is a question,’ then ‘what is an explanation’ and then the vastly more vexed problem of making an evolutionary explanation.  I will take this up after finishing with the tribe and territory.


Naked apes: There are benefits to being hairless.  Heat rejection made possible by our loss of body hair allows cursorial (persistence) hunting.  Here is our problem:  We cannot eat many plants.  Our digestive systems (without cooking and domestication via selective breeding of fruits and vegetables) are obligate non-vegetarian.  We are an omnivore, and meat, marrow and fat are a significant source of calories which are stored on the hoof, so to speak.  Other animals have processed vegetation into meat which we can use to fuel our large brains.  So we hunt.  But we do not have significant weapons.  We do not possess sharp teeth and fangs.  We are muscularly weak and rather slow.  We have reasonably good vision and hearing but a poor sense of smell.  We are not a very impressive predator.  But without fur coats we can reject metabolic heat at a greater rate than most other animals.  So, while many can run faster, we can run longer.  We are cursorial hunters, following and chasing another animal into their heat exhaustion.

That being said, I hasten to add that gathering, primarily by females, probably provided most of the calories more reliably in many ecologies that did hunting.  And to that I add that hunting was absolutely necessary for survival in many high latitude ecologies and in lower latitudes during Ice Ages.  And then to close the circle, man does not live by meat alone.  We are omnivores, not obligate carnivores, and require vegetables and fruits to avoid deficiency diseases.

Fire is our most ancient and fundamental technology.  Fire first conquered darkness and deterred predators, then increased both our food supply and our pleasure therein via cooking.  Fire is necessary in the development of pottery and glass.  But one of its greatest benefits was unlocking the secrets of metals via smelting, casting, forging and heat treating.  There are two other technologies which might compete with fire for primacy: one is a material and its manipulation – fiber – and the other is mainly an idea – the cutting edge.  Fiber plus the technological idea of weaving yields baskets, ropes and nets, and eventually clothing, which has had the enormous psychological effect of hiding skin and bodies, and reducing touch.  Cutting edges, first made with rocks (which are oxygenated compounds of metals) and then made of elemental (copper) and alloyed (bronze and iron) metals, made a wide range of other technologies possible, including improvements in fiber technology, and greatly increased both gathering and hunting efficiency.

See for more information on fire.

Preferred group size: the observation by biologists and anthropologists that there are species-specific typical or preferred group sizes go back a long time.  The number of individuals comprising a group has been called ‘the magic numbers.’  For humans, the magic number varies around 25 to 50 at the low end and 150 at the high end.  In recent years management theory has used these numbers to develop guidelines for the number of individuals on a specific project.  Computer game designers have also considered these numbers in the design of interactive games.

Social brain hypothesis: In the 1970’s the name given to the range of individuals in a group was the ‘magical number’ because it had been observed in a wide range of species and their groups but a reasonable explanation had not yet been developed.  In the 1990’s Robin Dunbar did a major statistical study on brain size vs preferred social group size to support the idea that our relatively large brain size evolved to solve the problem of gluing a number of highly complex and variable individuals into a social group that met both individual and social needs to an adequate degree.  There is an intimate reciprocal relationship between complex behavior, brain size, and social group size, each affecting the other.   Robin’s name is now associated with this number as Dunbar’s Number.

There is another number of great importance: the low bound on the number of individuals in a group that is required to avoid genetic in-breeding.  Craig Childs, in his book Atlas of a Lost World: Travels in Ice Age America, a study of the populating of the Americas via a land bridge from Siberia, suggests that a minimum number would be about 160.  This is the number of breeding individuals and not the group size.  There are a wide range of estimates of this number and a source for 160 is here:

That number does not include the non-breeding individuals, the young and old.  Adding those would at least double and maybe nearly triple the number of individuals in a fully complemented social group.  The importance of this number is that it is much larger than the Dunbar Number for humans which includes the non-breeding members.  The implication is that our social group size is not coterminous with our required breeding group and therefore we have built in out-breeding behaviors.

The kibbutz, or Westermarck effect is one out-breeding behavior: mates are typically not chosen from within the natal group but from a neighboring group.  Propinquity, particularly from birth to age 6, results in loss of sexual attraction at adolescence.  Propinquity at adolescence is exciting.  A mate from another group would be attractive.  Voluntary transfer at adolescence from the natal group to a nearby group is another behavior.  Yet another is female choice.  One example from chimpanzees was a female in estrus disappeared from her group for several weeks and returned quite pregnant for her parturition.

There is one more magic number, the number of individuals comprising the out-breeding group.  John Pfeiffer, in his book, The Emergence of Man, suggests that this number is about 500 and is comprised of neighboring groups with similar or related languages.  Language is one of the fundamental tribal identifiers and mates may be exchanged within these larger tribal boundaries but not beyond.

I have hidden in plain sight the development of these neighboring groups.  Story telling plays an integral role in this process and this will be a topic for a forthcoming essay.  I have adumbrated that in the first sentence of this essay: “Stories develop within the ambit of the tribe and tribalism thus dividing one tribe from another.”

Remaining on the sidelines of our civilization are relict populations of hunter gatherers and primitive agriculturalists, who seem to be doing quite well, thank you, except that they are losing their habitat to civilized development.  To borrow yet another phrase, this from John Steinbeck’s novel Grapes of Wrath, they are being “tractored off” of their land.

During the Great Depression and the Dust Bowl, the homes, barns and outbuildings of bankrupt farmers were destroyed by crawler tractors.  This drove the famers and their families off their land and onto the road.  They had been tractored off.  I think, once again, of the photograph of the favelas of Sao Paulo, Brazil, and wonder how many of the residents were tractored off their ancient tribal territories in the encroaching evolution of civilization.  Loss of land, and of tribe.  I have a memory that I have been unable to verify, a memory of the heart-rending cry in Alan Paton’s novel Cry the Beloved Country “the tribe is broken and nothing can take its place.”  Civilization doesn’t.  Civilization can’t take the place of the tribe.  We have lost something of ultimate value.  To this cri d’coeur I add “and the land is lost.”

I was browsing the web and came across the phrase “the increasing meaninglessness of life” in an essay about modern civilized life and loss of spiritual values.  This was at the same time as I was reading about the populating of the Americas in Child’s book Atlas of a Lost World.  His picture was of triumphant tribalism, groups of foragers exploring the riches of the New World. How excited they must have been, exploring new land.  How did we get from there to whinging about meaninglessness?  We lost the tribe, the small scale tightly bound social group, the source and measure of our social nature, and of our values and morality.  Some of our tribal social needs have been imposed upon the pair bond and the family, which are not capable of supporting such a load.  Some are found in small scale sub-groups such as clubs and other associations.  Some needs are simply un-satisfied resulting in frustration and various psychological repression and conversion mechanisms.

Tribe and land, the mosaic of identity, are one source of our behavior controls and our survival rules.  We are civilized.  We are frustrated tribalists cutoff from tribe and land.  We are perforce unsane.