From time to time, I start to think about the absolute miracle that is this business of meeting complete strangers all the time on the street and not going out on the arm with the guys, or getting beaten up by them. Yes, I know the statement seems completely unreasonable, but the fact is that this wonderful invention of human society known as “tolerance of strangers” is by no means inevitable. He doubts? Ask the chimpanzees.
Our closest living relatives, members of the species pan troglodytes, they simply have no idea what it would be like to exchange pleasantries with some chimpanzee they’ve just met. In the wild, all interactions between members of one group of these great apes with members of another chimpanzee community end in flight or confrontation.
The only exception—still quite relative—involves the transfer of females who have just reached reproductive age from one group to another. Like many human cultures, chimpanzees are considered patrilocal, meaning males stay in the same pack for life, while females leave their family (not to marry, as they are not monogamous, but to mate with multiple males). . And that doesn’t mean that females alone can’t be beaten, sometimes to death, when members of another group bump into them in the woods. All this means that, in terms of social interaction, chimpanzees spend their lives confined to a network that gathers, at most, about a hundred individuals.
Even smaller-scale human societies, the so-called mobile hunter-gatherers, deal with this problem in a much more sophisticated way. While universal harmony is far from reigning among groups with this social organization, the relatively peaceful exchange of news, raw materials, technologies, and sexual partners extends across much wider networks, with thousands of individuals. Kinship and friendships transcend bands (as basic social units are called, roughly the same size as chimpanzee groups).
Which means we have a small conundrum: given this chasm, how did humans become more tolerant of strangers? In a word, bonobos (pan paniscus), our other first cousins.
These great apes are most famous for their promiscuous and seemingly idyllic sex lives, but there was also evidence that most interactions between different groups of the species are peaceful. However, there were still doubts about what exactly was happening in these cases. One possibility is that the seemingly smooth encounters between different groups were actually just the interaction between subgroups of a single large community.
A study that appeared recently in the American trade journal PNAS seems to have solved the riddle, in favor of the idea that, in fact, bonobos are excellent political animals. A trio of researchers led by Liran Samuni, a primatologist at Harvard University, used sophisticated statistical methods to dissect the links between bonobos living in Kokolopori, in the Democratic Republic of Congo.
The conclusion: groups are real social units, with their own identity and preferential interaction among their own members — but even so, they do not fall into a fight when they encounter other groups, in fact, quite the opposite.
Our ability to bond with people very different from us is, therefore, perhaps as old an element of our lineage as chimpanzee xenophobia. We are a complicated primate — which, if it gives us a lot of work, is also reason to have some hope.
