HENRY

This week’s Science is a special issue on social cognition, and has a bundle of fun little articles (all of which are subscription only), starting with a review of “Social Components of Fitness in Primate Groups” by Joan Silk:

There is much interest in the evolutionary forces that favored the evolution of large brains in the primate order. The social brain hypothesis posits that selection has favored larger brains and more complex cognitive capacities as a means to cope with the challenges of social life. The hypothesis is supported by evidence that shows that group size is linked to various measures of brain size. But it has not been clear how cognitive complexity confers fitness advantages on individuals. Research in the field and laboratory shows that sophisticated social cognition underlies social behavior in primate groups. Moreover, a growing body of evidence suggests that the quality of social relationships has measurable fitness consequences for individuals.

This is followed by Herrmann et al’s “Humans Have Evolved Specialized Skills of Social Cognition: The Cultural Intelligence Hypothesis“, where they test the idea that one of the reasons that humans are smart is because we’ve developed a special set of cognitive skills for handling social tasks:

Humans have many cognitive skills not possessed by their nearest primate relatives. The cultural intelligence hypothesis argues that this is mainly due to a species-specific set of social-cognitive skills, emerging early in ontogeny, for participating and exchanging knowledge in cultural groups. We tested this hypothesis by giving a comprehensive battery of cognitive tests to large numbers of two of humans’ closest primate relatives, chimpanzees and orangutans, as well as to 2.5-year-old human children before literacy and schooling. Supporting the cultural intelligence hypothesis and contradicting the hypothesis that humans simply have more “general intelligence,” we found that the children and chimpanzees had very similar cognitive skills for dealing with the physical world but that the children had more sophisticated cognitive skills than either of the ape species for dealing with the social world.

Next up is another paper by Robin Dunbar and Susanne Shultz on Evolution in the Social Brain (henry covered their previous paper too):

The evolution of unusually large brains in some groups of animals, notably primates, has long been a puzzle. Although early explanations tended to emphasize the brain’s role in sensory or technical competence (foraging skills, innovations, and way-finding), the balance of evidence now clearly favors the suggestion that it was the computational demands of living in large, complex societies that selected for large brains. However, recent analyses suggest that it may have been the particular demands of the more intense forms of pairbonding that was the critical factor that triggered this evolutionary development. This may explain why primate sociality seems to be so different from that found in most other birds and mammals: Primate sociality is based on bonded relationships of a kind that are found only in pairbonds in other taxa.

Heading right down the cognitive path is Prospection: Experiencing the Future by Gilbert and Wilson, who review some recent work on “mental time travel”:

All animals can predict the hedonic consequences of events they’ve experienced before. But humans can predict the hedonic consequences of events they’ve never experienced by simulating those events in their minds. Scientists are beginning to understand how the brain simulates future events, how it uses those simulations to predict an event’s hedonic consequences, and why these predictions so often go awry.

Posted on September 9th, 2007 by Simon Greenhill