Hanging Out with Females Makes Primate Males Smarter

In New Scientist:

Brain structures in primates have developed due to different pressures on males and females to keep up with social or competitive demands, a new study suggests.

A comparison of brains from 21 primate species, including gorillas and chimps, suggests that those with greater male-on-male competition have more brain matter devoted to aggression and coordination. Whereas those species in which there is more social mixing between males and females have evolved bigger brains with higher-level thinking.

Competition for status and mates among primates might have influenced brain evolution, the researchers say. They add that contrasting brain types resulting from behavioural differences between the sexes might be a factor in other branches of mammalian brain evolution beyond anthropoid primates.