The Pleistocene Social Contract: Culture and Cooperation in Human Evolution

Kim Sterelny

My review 2022-02-14

A short, well-argued book about the prerequisites and possible scenarios for the evolution of Homo sapiens, with a focus on special collaborative and cultural capabilities of said species. As part of laying out his own arguments and hypotheses, Sterelny nicely reviews the currently known facts about the evolution of hominims since 7 million years ago, and comments on uncertainties and controversies.

Unfortunately, his text is so condensed that he sometimes just assumes that the reader has background knowledge of some examples and debates he mentions. For example, he mentions the interesting anthropological case of the conflict between the Nuer and Dinka peoples, but does not explain the background. This makes the text unsuitable for newcomers to the field.

From this and other texts I have read recently, it is clear that the sparseness of hard data points makes it practically impossible to produce solid hypotheses about the mechanisms that drove the evolution of cooperation and cumulative culture.

Discussing several controversies in this area, Sterelny argues that the effects of group selection may have played some role, but that several other recent contributions to the field have oversold the case. Sterelny offers a nuanced alternative which builds a case for the evolution of cooperation, culture and tribal sociality built mainly on traditional notions of individual selection. I believe his arguments are basically valid, although not flawless.

One of his main points is that the mobile hunter/gatherer mode of life was one of fundamental equality between people, at least within the sexes. It was the gradual shift to farming that created societies with high levels of inequality. But importantly, more sedentary hunter/gatherers in the anthropological record also show examples of pronounced inequality. Sterelny provides a set of scenarios explaining the possible mechanisms of the growth of inequality, which in my mind seem eminently plausible.

In the last section of the book, Sterelny concludes that the problem of cooperation and culture is basically one of how the initial establishment of cooperation occurred. He thinks that once a basic mode of cooperation was achieved, the benefits of it were so great that it becomes easier to explain how the positive feedback loops could maintain this cooperation, and allow further evolution. Maybe. I am more impressed by the conditionality of it all. There were so many things that had to come together to create Homo sapiens. Our existence is a stochastic phenomenon.