Essays
Essays
Hunter-Gatherer
About 200,000 years ago, when humans first appeared, they lived as hunter-gatherers in small nomadic bands of 25-35. About 50,000 years ago, in apparently a single ‘dispersal', they migrated out of Africa where they had originated, into Arabia and southern Asia, then to Malaysia, Australia, and New Guinea, not reaching Europe until perhaps 40 to 45,000 years ago. No matter where they settled, whether in the desert or the subarctic, they continued the hunter-gatherer life style, adjusting it to the locale.
Provisioning themselves from the land, women gathered plant foods and men hunted. When collecting plants, women often carried their infants in a leather sling, on their hip. Women gathering plants, and men hunting was the trend, but the variability was broad. In the Arctic there were no plants to gather, and people lived on meat and blubber.
In braving the blizzards and the freezing temperatures, Inuits proved the obvious: Human adaptability has no limits. The sharing of wives rather than practicing monogamy as nearly all hunter-gatherer bands did, was an Inuit adaptation to the Arctic. Men who belonged to the same hunting party, shared wives. The wives, all of whom were potential widows, were well served by this communal arrangement, for Arctic hunting is extremely risky. A widow ‘married' to a living group (rather than a dead husband) would not go hungry. Nor would her children.
In the dense forests, women (and sometimes children) drove animals into nets where men killed the ensnared animals; in harsh deserts, women brought back animals as well as plants. The occasional kangaroo or
cassowary, the large game men hunted, were often equaled in caloric value by the smaller game, the lizards, snakes, rodents, caught by women. Not all women returned with smaller game. Leaving their children home in the care of others, some women hunted as men did with bow and arrow. Even more remarkable are the groups in which men collected plant food!
Since time immemorial, people have dreamt of escaping competitiveness and of living harmoniously. Many of these seekers are ignorant of prehistory; ignorant of the achievements of their ancestors. They do not know that hunter-gatherers, their human ancestors, lived in an equitable society for almost 200,000 years! In a society with little economic division or social hierarchy, and few permanent leaders.
In some groups, women enjoyed greater sexual equality than at any other time in history. How did hunter-gatherers escape human competitiveness? How did they manage to live equitably for thousands of years?
In their small groups, they knew one another personally. Food was scarce. Not to the point of starvation. But unreliable. Had hunter-gatherer groups been large enough to eliminate personal recognition, would their equitable society have survived? Probably not. What if the group had remained small, but the food supply had become reliable, even abundant? This question has been ‘tested ‘ and given a clear answer.
Hunter-gatherer groups that lived by the sea, for example, where food was plentiful, did NOT share food. These groups lost their equitable society, became hierarchic, and divided into rich and poor. They acquired permanent leaders with special prerogatives - - the inequities of modern society!
There is reason to believe that all hierarchic groups, at some time in their history, had abundant food. Water provided the food in some cases: fish migrated into the streams near them; the open sea offered large fish. Land in other cases: herds of bison ran in the nearby fields. Sometimes cold weather accompanied the abundance of food. Then, groups were able to smoke salmon, dry bison, and be supplied throughout the winter. The storage of food destroyed the little that remained of the traditional hunter-gatherer band.
Groups that had been nomadic, moving every few months in search of food or water holes, became stationary. Now they remained in the same place long enough to grow and harvest small gardens. And they no longer lived in flimsy shelters that could be put up in a matter of a few hours, but in permanent houses.
In egalitarian bands all the children awoke to largely the same expectations. In hierarchic bands, children of the rich and poor awoke to distinctly different prospects: a day spent in the light of a well-placed father, vs. a day spent in the shadow of a lowly father. Hierarchical bands marked high and low status conspicuously, for instance, leaders did not have to hunt or fish for themselves, they were given food by others..
Some of the hierarchical groups added war, and fought viciously with their neighbors. Fights of this kind were relatively infrequent, not only among egalitarian groups, but among the remaining hierarchical bands as well. The warlike groups not only fought and took prisoners, they turned the prisoners into slaves.
If we look only at the egalitarian bands, that formed the majority, comprising perhaps over 90% of our prehistory, we are unprepared for the inequities of our modern world. But if we look at the remaining 10%, with its social hierarchy, war and slavery, the modern world ceases to be a mystery.
How does abundant food turn an egalitarian group into a hierarchical one? People share food when it is scarce or its supply is unreliable, But they do not share when food is abundant. They keep not only food for themselves, but the goods they receive when bartering with extra food. This too contrasts with what is done in a time of scarcity. When food is scarce, a gifted hunter who is lucky enough to barter his occasional extra food for a cow or horse will share the milk with other group members and allow them to use the horse.
Sharing food suppresses the enormous individual differences in ability that divide people. People of high ability, when sharing food with their neighbors, do not exploit their superior ability, to take advantage of their neighbors. Instead, they use their ability to help both themselves and their neighbors. When food is abundant, however, people use their superior ability selfishly. They use it to accumulate as much food as possible. A competition ensues among the able, won by the individual who is best able at translating his goods into power.
In time, this individual will establish himself as the leader of the band. Under his leadership, the cultural values of the egalitarian band, modesty and equality, will weaken, and the band will begin to accept the quite different values of the hierarchic band, stridency and self-promotion.
This change is not one that can be brought about in days, weeks or months. Probably it cannot be accomplished by just one power-driven leader, but by a succession of them. Overcoming the culture of the egalitarian band may take several generations.
Was the transition reversible? Since the change from scarce to abundant food was in all likelihood the key factor in converting an egalitarian group into a hierarchic one, would the opposite reverse the process? Would the depletion of a once abundant food supply restore a formerly egalitarian group to its original condition? would the group resume food sharing?
Data that bear on this question suggest that the answer is no. Hierarchic groups have been found to have a high density of people per unit food, and indeed some anthropologists have proposed this as the cause of hierarchic groups. A mistake, I suggest. It confuses the long-term consequences of a hierarchic group with the condition that caused the group to form in the first place.
Hierarchic groups, at least in their early stages, have an abundant supply of food. This abundance attracts people, leading in time to a high density of people. The abundant food supply may also increase the birth rate, contributing to the high density of people. Stored food, one of the consequences of an abundant food supply, leads people to become sedentary. People have a higher birth rate when sedentary. Probably the inter-birth interval declines, and so does the practice of infanticide common in nomadic groups.
People multiply, but not the food supply. As a consequence, the density of people per unit food increases. This may be the common fate of groups that begin with an exceptional food supply.
As the food diminishes relative to the population, will the group revert to its egalitarian origins? The data indicate that it will not. People at the top, who are least affected by any shortage of food, will not willingly give up their privileges. People at the bottom, who are most affected by a shortage of food, very seldom act forcibly to increase their privileges. On the few occasion in more recent history when the underprivileged did react, their revolutions did not produce an egalitarian society. They simply changed the membership of the privileged group.
Humans have a built-in inequality. Some are twice as smart as others, twice as sly, bold, cunning, etc. Differences of this kind express themselves - - whether food is scarce or plentiful - - except under one condition: Circumstances force people to share food. Sharing blocks the expression of individual differences in ability, producing, as it did in the case of the hunter-gatherers, an equitable society that lasted thousands of years.
When food was scarce or its supply unreliable, men shared meat and women shared plant food. The sharing of meat by men is generally regarded as a case of reciprocal altruism. An individual who has food gives it to those who do not, on the expectation that he will be given food if the tables are turned. Though a skilled hunter will, in the long run, doubtless give far more than he receives, reciprocal altruism is an insurance policy. Were the hunter to run out of food, he would be protected against disaster. Reciprocal altruism, though probably the best-fitting model of the alternatives, is not a complete success. It will not explain sharing in large groups. Even in small groups, there is evidence in favor of other models, including a kinship effect (more given to kin than non-kin), and so called ‘tolerated theft', meat obtained by insistent nagging (reminiscent of the scrounging by which chimpanzees obtain meat from an animal holding the kill).
Why do men hunt large game in the first place? They could obtain more food, with less risk, by combining the hunting of small game with gathering plants. But bold, successful risk-taking may attract sexual partners, and despite the belittling of the capture of large game, de rigeur in egalitarian groups, killing a large animal did not prevent the hunter from gaining prestige. Young unmarried men who are skilled hunters offered meat to women for sex. And men were not always upset when their wives participated. They enjoyed the meat.
In a literature largely written by men, one hears more about the meat men shared than of the plant food shared by women. Nevertheless, women in some groups routinely collected more plants, berries, nuts, roots, etc. than needed and gave them to other women who too collected more than they needed. Giving of this kind is not well explained by reciprocal altruism, or any of the other evolutionary models designed to explain altruism. On the contrary, it suggests that giving may be an intrinsic disposition in people, in women, at least. Giving may be an intrinsic disposition of men, too, though, in their case, because of the greater value of meat, the disposition to give may be suppressed.
Many hunter-gatherer bands, while largely devoid of both social and economic division, did not necessarily have harmonious relations. Not everyone got along. But this was not a difficult problem to solve. Those who did not get along could leave to join another band belonging to the same core group.
There were more serious imperfections. Men, in the same band, sometimes murdered one another over women. They did so despite (or perhaps because of) love affairs. How common were affairs? Common enough to lead to rules prescribing how an affair was to be conducted. Strictly forbidden was an affair with the brother or sister of one's spouse.
When living as hunter-gatherers humans acquired their basic nature. Not only language, which too often is taken to explain all of human uniqueness, but a number of other unique capacities as well. Three are especially critical for understanding people. First, theory of mind (our ability to explain the actions of others by ‘reading' their minds and attributing mental states to them, such as think, want, hope, etc.). Second, pedagogy (our unique disposition to teach one another). Third, reasoning of various kinds (inference, analogies, causal reasoning, etc.). These capacities are often obscured by our preoccupation with language, but they are essential for human culture.
Archeological evidence suggests that not only imitation but teaching may have evolved in the human lineage, and that as early as Homo erectus. Although the earliest tools of Homo erectus were quite variable, their ‘intermediate' tools were surprisingly uniform, suggesting imitation, one individual copying another. Their later tools are not only uniform but complex, too complex perhaps to have been made by imitation alone. French archeologists devised a clever way to estimate the complexity of a tool: They made the tool themselves! Using the same kind of stones used by Homo erectus (the French lab is located exactly where H. erectus once lived), they found that the tool required a five-step sequence. It would have been difficult to reproduce a sequence of this kind by imitation alone, some amount of correction or teaching was probably required, though the teaching need not have used language. The teacher could provide examples, and then nod approval/disapproval as the students attempted to duplicate them. But language could have been used, since endocasts suggest that the brain of Homo erectus contained Broca's area, a fundamental language area.
Flexibility, the capacity to respond adaptively to unforseen conditions, is distinctive of human intelligence. While human intelligence initially evolved to solve the problems of the world of the hunter-gatherer, it continues to serve humans in solving the very different problems of the modern world. Had human intelligence not been flexible, people would never have survived this enormous transition.
Some evolutionary psychologists claim that since evolution solves specific, not general, problems, there is no general purpose knowledge.' This claim may be true of crickets or ducks, but not of humans. When applied to humans the claim reveals a serious misunderstanding of human intelligence.
When a human cuts an apple with a knife, marks a paper with a pencil, cooks meat over a fire, he recognizes these actions as examples of causal transformation. Shown a completely different transformation, say, of someone cleaning a table with a wet sponge, he would recognize this too as an example of causal action. Humans recognize physically different examples of cause because the human representation of all concepts - - not only that of causal action - - is abstract or general. Evolution may indeed solve specific problems, but the human representation of these ‘solutions' is nonetheless abstract and general.
Perhaps the earliest indication of human flexibility lay in the dawn of the species when humans invented technologies - - fire, cooking, clothing, shelters - - that sealed their future. Equipped with these technologies they were able to drift out of Africa, spread across Asia into Europe, and, as hunter-gatherers, settled in virtually every corner of the world. By contrast, chimpanzees have remained in the same corner of Africa for the last 5 million years, lacking the cognition to produce the technologies on which migration depends.
The loss of game, brought about by changes in climate, competition from other species, etc., is a common problem faced by many species. Not all species survive. Those that do are rescued by evolution. Over the course of generations, survivors adapt to a new diet. But humans, when their supply of game collapsed, were not rescued by evolution, nor did they slowly adapt to a new diet over the course of generations. Humans changed their technology. Rather than foraging for plants and animals, they planted the former and domesticated the latter. A cognitive change. A change based on intelligence, not evolution. Humans were able to make this change because of their abstract understanding of causality. They were able to recognize that seeds planted in the earth would grow into plants.
Is The Hunter-Gatherer Brain Different From The Modern Brain?
Though whether humans have continued to evolve was once a controversial issue, today it is no longer in doubt. Genetic modifications have definitely occurred since humans turned to agriculture in the past 10,000 years. The best documented modifications are in the digestive system, and in the immune system.
The rise of dairy farming between 5,000 and 10,000 years ago, caused a genetic modification that produced lactose tolerance in some adults. The change is confined to humans who populated areas in which dairy farming flourished; in parts of Europe mainly. Disease too has caused genetic changes. People with genotypes that confer resistance to a disease will have more offspring; the resulting natural selection will lead to an increase in the frequency of those who have the resistance-conferring genes. Though malaria is a scourge of mankind, it did not become one until after the invention of farming. The clearing of forests left pools of standing water in which mosquitoes could breed. Several genes have alleles that produce resistance to the malaria. About 6,000 years ago, one appeared in Africa; the other which appeared in southern Europe, the Middle East, and India, is estimated to be about 3,300 years old.
The ability to identify a genetic modification, to estimate its date of occurrence, to associate it with a physiological change, and to relate the modification to a known environmental or cultural event, provides clear evidence that humans have evolved in the past 10,000 years.
But which if any of these changes have an effect on human brain and intelligence? Genetic changes in lactose tolerance and disease resistance have no such effect. Are we to believe that we still have our stone age brain, that the modern human brain is the brain of the hunter-gatherer?
There are two challenges to this view: First, the genetic change which is responsible for the DRD4 7R allele, and second, the gene ASPM. DRD4 7R is an allele associated with both the attention-deficit/hyperactivity disorder and the personality trait of novelty seeking. ASPM has for millions of years been a specific regulator of brain size in the evolution of the lineage leading to Homo sapiens.
There is a suggestion that the DRD4 7R allele originated as a rare mutational event. Rare in that this mutation, unlike most, had a beneficial effect and thus increased in frequency in human populations by positive selection. Is the claimed ‘novelty seeking' beneficial? Even if we were to grant this claim, a predilection for novelty may have little effect on intelligence. If a novelty-seeker were to tackle problems a conservative person would shun, would this change the abstractness of stored information? the computational skills involved in reasoning? our social competence (the accuracy of the mental states we attribute to the other one)? Probably not.
Phylogenetic analysis of the gene ASPM has revealed ‘...its strong positive selection in the primate lineage leading to humans, especially in the last 6 million years of hominid evolution..' A contemporary genetic analysis now shows that ‘... one genetic variant of ASPM in humans arose only about 5800 years ago and ‘... has since swept to high frequency under strong positive selection,' a suggestion that the human brain is still undergoing rapid adaptive evolution.
The continued enlargement of the human brain would almost certainly lead to a change in human intelligence, but presently there is no evidence for either an enlargement of the brain, or a change in human intelligence. Paradoxically, there is a suggestion of the opposite change, a reduction in the size of the human brain! This suggestion comes from the fact that domestication of animals has led to a reduction in the size of the brain, and some anthropologists argue that humans, in going from foraging to agriculture, themselves underwent domestication. But this is a dubious claim. A farmer enjoyed none of the benefits of a domesticated animal. He was not fed, sheltered, and protected from predators. In the transition from forager to farmer, humans changed the kind of challenges they faced, not the number or severity of the challenges.
All the distinctive facets of human intelligence are seen in the activities of humans when they lived as hunter-gatherers. They talked. Women gathered in the morning to tell one another stories about "yesterday's" happenings; in some groups women punctuated their stories with visual symbols, iconic figures they drew in the sand. Men, sitting by camp fires in the evening, argued over the special traits of different animals. They honored first-hand knowledge over mere opinion. And with the same intensity we do today.
Hunter-gatherers taught one another. Parents taught their children the technologies on which their lives depended: How to butcher large animals, to turn animal hide into cloth. How to break ostrich shells into tiny pieces, then string them on leather thongs to make jewelry. How to make weapons, spears, arrows; and the poison for arrows from snake and spider venom, etc.
Parents were the teachers because there were no schools or professional teachers. Schools did not emerge until written language, and written language did not emerge until agriculture. Writing dramatically transformed human knowledge. Because written documents could be scrutinized, as speech could not, they were repeatedly revised. Their revision lead to the elimination of redundancy, the compacting of arguments, and the discovery of higher order generalizations. Under the impact of writing, informal knowledge, such as the hunter-gatherer's folk-knowledge of plants and animals, was systematized and turned into science. Often-told tales and stories became literature, and informal calculations, became logic and mathematics. The specialized knowledge produced by writing culminated in schools and teachers, depreciating the parent's folk-knowledge, ultimately putting them out of work as teachers.
In conversing with one another, in reading one another's minds, in copying one another's actions, in teaching one another, humans profit from one another to an uncanny degree. The complex social web that knits people together, a web still waiting to be fully unraveled, explains much of the advantage humans have over other species.
By David Premack