There is a very striking difference between even the simplest ethnographically known human societies and those of the chimps and bonobos. Chimp and bonobo societies are closed societies: with the exception of adolescent females who disperse from their natal group and join a nearby group (never to return to their group of origin), a pan residential group is the whole social world of the agents who make it up. That is not true of forager bands, which have fluid memberships, and (...) regular associations with neighbouring bands. They are components of a larger social world. The open and fluid character of forager bands brings with it many advantages, so the stability of this more vertically complex form of social life is not difficult to explain, once it establishes. But how did it establish, if, as is likely, earlier hominin social worlds resemble those of our close pan relatives in the suspicion (even hostility) of one band to another? How did hominin social organisation transition from life in closed bands, each distrustful of its neighbours, to the much more open social lives of foragers? I will discuss and synthesise two approaches to this problem, one ecological, based on the work of Robert Layton and his colleagues, and another that is organised around an expansion of kin recognition, an idea primarily driven by Bernard Chapais. The paper closes by discussing potential archaeological signatures both of more open social worlds, and of the supposed causal drivers of such worlds. (shrink)

This article seeks to identify at what point in hominid evolution language would have become adaptive. It starts by recalling the distinction between kin-selected altruism and reciprocal altruism, noting that the former is characteristic of social insects while the latter is found among some species of social mammal. Reciprocal altruism depends on the exchange of information assuring partners of the other’s continued friendly intent, as in the iterated prisoner’s dilemma. The article focuses on species that practice “fission–fusion”: social behaviour, where (...) the alternation between larger and smaller parties creates greater uncertainty as to individuals’ continued commitment to reciprocity. The greatest uncertainty arises in “atomistic” fission–fusion, where individuals leave and join foraging groups independently. Chimpanzees, bonobos, and human hunter–gatherers practice this type of social behaviour. There is less uncertainty where the smaller social unit is an extended family, as among vampire bats, chacma baboons, and savanna elephants. A comparison of the repertoire of calls and gestures among these species indicates that chimpanzees and bonobos have the largest repertoires. I then point out that, thanks to the higher proportion of meat in the diet, hunter–gatherers must live in far more dispersed communities than chimpanzees or bonobos, yet they practice more complex patterns of cooperation and reciprocity. This, I argue, created a social environment in which language became particularly adaptive. Homo heidelbergensis is identified as the key species in which language could have originated, during the transition between the Lower and Middle Paleolithic. (shrink)

This paper introduces a Special Issue of Topoi entitled "Archaeology and philosophy".

Human societies are examined as distinct and coherent groups. This trait is most parsimoniously considered a deeply rooted part of our ancestry rather than a recent cultural invention. Our species is the only vertebrate with society memberships of significantly more than 200. We accomplish this by using society-specific labels to identify members, in what I call an anonymous society. I propose that the human brain has evolved to permit not only the close relationships described by the social brain hypothesis, but (...) also, at little mental cost, the anonymous societies within which such alliances are built. The human compulsion to discover or invent labels to “mark” group memberships may originally have been expressed in hominins as vocally learned greetings only slightly different in function from chimpanzee pant hoots (now known to be society-specific). The weight of evidence suggests that at some point, conceivably early in the hominin line, the distinct groups composed of several bands that were typical of our ancestors came to be distinguished by their members on the basis of multiple labels that were socially acquired in this way, the earliest of which would leave no trace in the archaeological record. Often overlooked as research subjects, these sizable fission-fusion communities, in recent egalitarian hunter-gatherers sometimes 2,000 strong, should consistently be accorded the status of societies, in the same sense that this word is used to describe tribes, chiefdoms, and other cultures arising later in our history. The capacity of hunter-gatherer societies to grow sufficiently populous that not all members necessarily recognize one another would make the transition to larger agricultural societies straightforward. Humans differ from chimpanzees in that societal labels are essential to the maintenance of societies and the processes giving birth to new ones. I propose that anonymous societies of all kinds can expand only so far as their labels can remain sufficiently stable. (shrink)