GELIFES Seminars - Sue Healy

Sue Healy (University of St Andrews)

The evolution of brain size - Do we have a good explanation yet?

Disbelief that the challenges posed by an animal’s physical (which includes interacting with food, predators, prey, and so on) environment could have produced the extraordinary cognitive capacities of some primates, including humans, lead to the proposal that the social environment was key. The resulting ‘Social Intelligence Hypothesis’, with the incorporation of data on brain size, later became the ‘Social Brain Hypothesis’. This hypothesis has been strongly favoured as an explanation for both ‘complex’ cognitive abilities and for enlarged brains. Four decades on, however, the evidence remains equivocal. I will discuss evidence for why this might be so and for other hypotheses, which also vary in their support.