Altruism: Not Just for Humans Anymore
True altruism has long been thought a uniquely human attribute, but that's changing rapidly. It appears likely that altruistic behavior predates the evolution of Homo sapiens, as demonstrated in a study just published by the Max Planck Institute for Evolutionary Anthropology.
Spontaneous Altruism by Chimpanzees and Young Children
People often act on behalf of others. They do so without immediate personal gain, at cost to themselves, and even toward unfamiliar individuals. Many researchers have claimed that such altruism emanates from a species-unique psychology not found in humans' closest living evolutionary relatives, such as the chimpanzee. In favor of this view, the few experimental studies on altruism in chimpanzees have produced mostly negative results. In contrast, we report experimental evidence that chimpanzees perform basic forms of helping in the absence of rewards spontaneously and repeatedly toward humans and conspecifics. In two comparative studies, semi–free ranging chimpanzees helped an unfamiliar human to the same degree as did human infants, irrespective of being rewarded (experiment 1) or whether the helping was costly (experiment 2). In a third study, chimpanzees helped an unrelated conspecific gain access to food in a novel situation that required subjects to use a newly acquired skill on behalf of another individual. These results indicate that chimpanzees share crucial aspects of altruism with humans, suggesting that the roots of human altruism may go deeper than previous experimental evidence suggested.
I've highlighted one sentence in the abstract above because it's fascinating that the chimpanzees in question not only would act on behalf of unrelated chimps but also on behalf of a member of an entirely different, albeit closely related, species. It leaves me wondering, firstly, whether chimpanzees might do the same thing for a fellow ape of another species — will chimps act altruistically toward a gorilla? It's known that wild chimps hunt and consume monkeys, which isn't exactly altruistic. What motivates such behavior in these primates? Secondly, in light of the ability of chimpanzees to think and emote in ways not terribly different from we humans, I can't help but wonder what was going through the minds of the apes in this study when they had the opportunity for altruistic behavior toward a human. Do chimps look into human eyes and see that same spark of awareness that we do when we look into theirs?
Debates about altruism are often based on the assumption that it is either unique to humans or else the human version differs from that of other animals in important ways. Thus, only humans are supposed to act on behalf of others, even toward genetically unrelated individuals, without personal gain, at a cost to themselves. Studies investigating such behaviors in nonhuman primates, especially our close relative the chimpanzee, form an important contribution to this debate. Here we present experimental evidence that chimpanzees act altruistically toward genetically unrelated conspecifics. In addition, in two comparative experiments, we found that both chimpanzees and human infants helped altruistically, regardless of any expectation of reward, even when some effort was required, and even when the recipient was an unfamiliar individual—all features previously thought to be unique to humans. The evolutionary roots of human altruism may thus go deeper than previously thought, reaching as far back as the last common ancestor of humans and chimpanzees.
I suspect that we're one day going to figure out that altruism goes back much further than this. While I haven't done anything resembling a formal study of their behavior, I have observed what looks like altruistic behavior in adult raccoons. I suspect, in fact, that we will someday find that altruism is a common trait in social mammals and extends far further back into evolutionary history than has previously been demonstrated.
As research methods and technology improve, we humans are finding more and more ways in which we aren't so unique after all. We are, indeed, much more intimately connected with the other living things with which we share this world than was suspected just a few decades ago. It makes perfect sense from an evolutionary point of view that this should be the case. Indeed, we should not expect to find that very much about us is novel. If we don't cling to antiquated theological notions of exceptional status for humanity, we stand to really get a grasp on what it means to be a human being. In that regard, the chimps in this study may be doing something for our species that goes beyond providing yet more data points that support a scientific theory. They may effectively be holding up a mirror to us that shows us how we came to be us... where we went right and where we've gone wrong, too.
