Book review author

Efforts to understand how ecology and evolution shape human behaviour rely, at least in part, on studying the social dynamics of non-human primates. On page 1160, Sarah Brosnan, an assistant professor of psychology at Georgia State University in Atlanta, reviews three books that detail the intimate social interactions between gorillas, chimpanzees and rhesus macaques. It is hardly monkey business: the politics, plotting and power struggles would make Machiavelli proud, Brosnan tells Nature.

Two of the books reference Renaissance philosopher Niccolo Machiavelli. Why?

All three books focus on the evolution of social behaviour, specifically on how individuals live in groups. Machiavelli suggested that, as a monarch, it is better to be feared than loved, which is reminiscent of the interplay of power, sex and politics seen in primates. Frans de Waal's book Chimpanzee Politics, for example, chronicles the ever-shifting alliances among three high-ranking males trying to lead a group. The coalitions and power strategies seem to be similar to office politics of contemporary humans.

On the basis of your experience, which primate group is most manipulative?

Quite possibly humans. Among non-human primates, I think apes are the most intentionally manipulative. They are best able to conduct behaviours that will gain them something in the long run, even if there is a short-term cost.

Did any of the books shed light on primate social behaviour?

Gorilla Society by Alexander Harcourt and Kelly Stewart made an explicit effort to calculate the most advantageous behaviour for a gorilla in any situation by measuring the costs and the benefits of alternatives. For example, you rarely see a hostile takeover of gorilla harem societies. Even though there would be a short-term benefit to the new male, it doesn't make long-term sense, because female gorillas have a lot of control over their own decisions. They could leave the new male after he had gone to considerable effort to acquire them.

Which book relates most to your work?

I study cooperation, economic behaviour and prosocial behaviour — that is, behaviour that is beneficial to others — in chimpanzees and capuchin monkeys. All three books investigate the occurrence of various prosocial behaviours, documenting the situations in which they are likely to occur. It is interesting to speculate about what conditions led some species to evolve more prosocial behaviours.