Human beings are the product of a few million years of evolution. Awareness of this is part of what it means to be modern. But most of the time this recognition remains general and vague. We get along just fine without thinking about the scale of the processes involved. We act as if a thousand years is a long time; it can be a strain to imagine the world of a few decades ago. It is hard to reckon just how thin a slice of human time is there in recorded history. That we ever developed the capacity to record things at all is strange and improbable. As recently as ten or twelve thousand years ago, our ancestors devoted most of their waking hours to finding enough calories to stay alive.
“To date,” writes Michael Tomasello, co-director of the Max Planck Institute for Evolutionary Anthropology in Leipzig, “no animal species other than humans has been observed to have cultural behaviors that accumulate modifications and so ratchet up in complexity over time.” At some point that complexity begins to spike -- an exponential surge that comes to seem almost normal. But how is it possible?
In Why We Cooperate, just published by Boston Review Books , Tomasello gives a succinct account of his work with a research team conducting comparative studies of the behavior of human infants and our closest primate relations, especially chimpanzees.
Their findings suggest that we are distinguished, as a species, by capacities for empathy, generosity, cooperation, and a sense of fair play. Some of these tendencies are found among the great apes, but not to anything like the degree to which they manifest themselves in children from very early in their development. These distinctive capacities form the bedrock of our capacity to accumulate, over time, not just wealth but complex behavior.
The new book -- based on the Tanner Lectures  delivered by Tomasello at Stanford University in early 2008 -- is a lay reader's introduction to work described in The Cultural Origins of Human Cognition (Harvard University Press, 1999) and Origins of Human Communication (MIT Press, 2008). Peers who comment on his work in the “forum” section of Why We Cooperate sometimes question the degree to which these abilities are hard-wired into us -- rather than being acquired through, or at least stimulated by, nurture and communication. But they concur that Tomasello and his team have opened up fruitful lines of inquiry into the source and nature of human development.
There is evidence, Tomasello writes, “that from around their first birthdays -- when they first begin to walk and talk and become truly cultural beings -- human children are already cooperative and helpful in many, though obviously not all, situations.” Faced with an adult they have never met before, for example, an infant between the ages of 14 and 18 months will help with “everything from fetching out-of-reach objects to opening cabinet drawers when the adult’s hands are full.”
This behavior is not the work of little rational-choice theorists in diapers. Children who were consistently rewarded for their assistance were found to be less helpful in subsequent experiments. Chimpanzees, too, were found to possess some inclination toward altruism. The major distinction on this point is that small children are both better able and more willing to share information in order to be helpful -- for example, by pointing out the location of a stapler whose whereabouts in the laboratory the child knows. While apes are capable of some very limited exchanges with humans, their messages tend to be self-interested (helping convey where a tool is that will be useful in getting them food) and they do not teach each other to communicate.
As they get older, writes Tomasello, the “relatively indiscriminate cooperativeness” of human children “becomes mediated by such influences as their judgments of likely reciprocity and their concern for how others in the group judge them....” This is not a matter of self-interest alone -- of doing unto others just as generously as they do unto you. The knack for moral bookkeeping does develop, of course. But first we acquire a sense that there are general rules for how things ought to be done, and that everyone ought to abide by them.
Three year-old children were shown a game that could be played by one person. “When a puppet later entered and announced that it, too, would play the game, but then did so in a different way,” reports Tomasello, “most of the children objected, sometimes vociferously. The children’s language when they objected demonstrated clearly that they were not just expressing their personal displeasure at a deviation. They made generic, normative declarations like, ‘It doesn’t work like that,’ ‘One can’t do that,’ and so forth.”
This is intriguing because the children’s perspective is disinterested. “It is one thing to follow a norm ... to avoid the negative consequences of not following it,” says Tomasello, “and it is quite another to legislate the norm when not involved oneself.”
In the case of the puppet experiment, I suppose “enforce” is a more appropriate word than “legislate.” But either way, it suggests the early development of a capacity to grasp the principle of a common and impersonal norm.
This both reflects and reinforces our capacity for cooperative action -- which may be the very thing that distinguished our hominid ancestors from other primates. Groups of small children “engage in all kinds of verbal and nonverbal communication for forming joint goals and attention and for coordinating their various roles in the activity,” says Tomasello, while his colleagues find nothing comparable to this range and complexity of cooperation among the great apes.
"Indeed,” he writes, “I believe that the ecological context within which these skills and motivations developed was a sort of cooperative foraging. Humans were put under some kind of selective pressure to collaborate in their gathering of food -- they became obligatory collaborators -- in a way that their closest primate relatives were not.... We could also speculate that since hunter-gatherer societies tend to be egalitarian, with bullies often ostracized or killed, humans underwent a kind of self-domestication process in which very aggressive and acquisitive individuals were weeded out by the group.”
Thanks to millennia of progress, we have reached a plateau of development where it is commonly accepted that existence is a war of all against all, and Donald Trump is taken to embody the traits that drove human evolution itself. (Otherwise he might look like the missing link with a hairpiece.)
None of this makes for optimism about our next ten thousand years or so -- or decade, for that matter. Hard as it is to wrap one’s mind around the depths of time and transformation involved in reaching this stage of civilization, it can be still more difficult to imagine how we can continue. The scale of possible aggression now -- let alone the unintended consequences of raw acquisitiveness -- go beyond anything our primate brains are quite ready to picture.
But for all that, the research by Tomasello and his associates is at least somewhat encouraging. It suggests that collaboration, sharing, and even generosity are not late developments in human existence -- merely secondary or superfluous capacities. They are essential. They came first. And they could yet assert themselves as a basis for reorganizing life itself.
Then, perhaps, our prehistory would come to an end -- and something like a civilization worthy of human beings would begin.