The human chimera – part lion, part goat

Richard Wrangham embraces controversy, and appears to enjoy munching apples from carts he upsets himself. While his new book seems to be the history of an amalgam of moral and political virtues and vices, its thesis is actually the large claim that these have evolved; and he has no compunction about writing that the foundation stone of good behaviour is the possibility of capital punishment (against it though he is in today’s world).

It’s not just that the logic of his argument requires this hypothesis; he has found examples of premeditated (‘proactive’), co-operative (‘coalitionary’) killing in the Pleistocene record, providing an empirical basis for his claims about our evolution. Chimpanzees have (reactive) murderous rages. There are also many attested examples of male chimpanzees bullying their most frequent sex partner, and of them committing infanticide, enough to cause us to look for the adaptive value of such behaviour (in both cases such proactive aggression increases the male’s chances of perpetuating his own genes). Proactive aggression, Wrangham argues, provides a necessary evolutionary curb on the reactive sort.

Wrangham is British, and holds the chair of biological anthropology in the newish department of human evolutionary biology at Harvard. Like his fellow anthropologist, the late Sidney Mintz (also Richard Dawkins, Steven Pinker and Matthieu Ricard), Wrangham’s academic work changes our ideas about everyday life. In Catching Fire: How Cooking Made Us Human (2009), he made the once startling, now easy-to-accept, claim that the mastery of fire allowed our ancestors to evolve bigger brains by reducing the larger digestive apparatus needed to extract nutrition from raw food — that learning to cook (meat and grains) was essential to the evolution of our hunter-gatherer species. (What would be the consequences for the future development of H. sapiens of adopting a vegan diet?)