Within paleoanthropology, the origin of behavioral modernity is a famous problem. Very large-brained hominins have lived for around half a million years, yet social lives resembling those known from the ethnographic record appeared perhaps 100,000 years ago. Why did it take 400,000 years for humans to start acting like humans? In this article, I argue that part of the solution is a transition in the economic foundations of cooperation from a relatively undemanding form, to one that imposed much more stress (...) on human motivational and cognitive mechanisms. The rich normative, ceremonial, and ideological lives of humans are a response to this economic revolution in forager lives; from one depending on immediate return mutualism to one depending on delayed and third-party reciprocation. (shrink)

This chapter compares the social behaviour of human hunter-gatherers with that of the better-studied chimpanzee species, Pan troglodytes, in an attempt to pinpoint the unique features of human social evolution. Although hunter-gatherers and chimpanzees living in central Africa have similar body weights, humans live at much lower population densities due to their greater dependence on predation. Human foraging parties have longer duration than those of chimpanzees, lasting hours rather than minutes, and a higher level of mutual dependence, through the division (...) of labour between men and women ; which is in turn related to pair-bonding, and meat sharing to reduce the risk of individual hunters' failure on any particular day. The band appears to be a uniquely human social unit that resolves the tension between greater dispersion and greater interdependence. (shrink)

Building on Dor’s theory of language as a social technology for the instruction of imagination, I suggest that autobiographical memory evolved culturally as a response to the problems of false memory and deliberate deceit that were introduced by that technology. I propose that sapiens’ linguistic communication about past and future events initially occurred in small groups, and this helped to correct individual memory defects. However, when human groups grew in size and became more socially differentiated, and movement between groups prevented (...) story-verification, misattributions of events became more common. In such conditions individuals with better autobiographical memory had an advantage because they could evaluate their own contents and sources of information, as well as that of others, more accurately; this not only benefitted them directly, but also improved their reliability as social partners. Autobiographical memory thus evolved in the context of human linguistic communication through selection for communicative reliability. However, the advantages of imagination, which enables forward-planning and decision-Making, meant that memory distortions, although controlled and moderated by autobiographical memory, could not be totally eradicated. This may have driven the evolution of additional forms of memory control involving social and linguistic norms. I interpret the language and the social norms of the Pirahã as the outcome of the cultural-evolutionary control of memory distortions. Some ways of testing aspects of this proposal are outlined. (shrink)

Accounts of language evolution have largely suffered from a monolingual bias, assuming that language evolved in a single isolated community sharing most speech conventions. Rather, evidence from the small-scale societies who form the best simulacra available for ancestral human communities suggests that the combination of small societal scale and out-marriage pushed ancestral human communities to make use of multiple linguistic systems. Evolutionary innovations would have occurred in a number of separate communities, distributing the labor of structural invention between populations, and (...) would then have been pooled gradually through multilingually mediated horizontal transfer to produce the technological package we now regard as a natural ensemble. (shrink)

Darwin's inner voice -- Living the virtuous life -- Of altruism and free riders -- Knowing our immediate predecessors -- Resurrecting some venerable ancestors -- A natural Garden of Eden -- The positive side of social selection -- Learning morals across the generations -- Work of the moral majority -- Pleistocene ups, downs, and crashes -- Testing the selection-by-reputation hypothesis -- The evolution of morals -- Epilogue: humanity's moral future.