politricks are innate to you humans...,

royalsocietypublishing |  Humans are perhaps the most social animals. Although some eusocial insects, herd mammals and seabirds live in colonies comprising millions of individuals, no other species lives in such a variety of social groups as Homo sapiens. We live in many different sized societies, from small, nomadic hunter-gatherer societies to cities consisting of millions of people living in close proximity; we form special social bonds with kin and many of us make lifelong commitments to one socio-sexual partner, represented in the shape of a marriage.

Although the fledgling concept of social intelligence was formulated over 50 years ago by Chance & Mead (1953), and more explicitly by Jolly 13 years later (1966), it was perhaps Nick Humphrey's (1976) seminal paper on the ‘social function of intellect’ that paved the way for the past 30 years of productive research in so many seemingly unrelated areas of the biological and social sciences. It is Nick's significant contributions, as evidenced by the number of quotations to his work in this special issue, and the anniversary of the birth of the ‘social intelligence hypothesis’ (SIH), that were celebrated at a Discussion Meeting of the Royal Society on 22 and 23 May 2006 and which form the basis of this special issue.

Humphrey (1976) argued that the physical problems which primates face in their day-to-day lives, such as finding and extracting food or hunting and evading predators, are not sufficient to explain the differences in intellectual capabilities of animals in laboratory tests. Indeed, many animals with very different levels of cognitive ability have to solve similar kinds of problems in their natural environment. So, why do primates, especially humans, have such large brains? Observations of social groups of gorillas in the field and macaques at the Sub-department of Animal Behaviour, Madingley, led Humphrey to suggest that recognizing, memorizing and processing ‘technical’ information was not the driving force behind the evolution of primate intelligence. He proposed that it was the intricate social interactions of these animals, their ability to recognize individuals, track their relationships and deceive one another, which occupied their time and substantial brainpower. In particular, it was Humphrey's emphasis on the importance of predicting and manipulating the behaviour and minds of conspecifics which led to the development of ‘theory of mind’ as a major research focus in both comparative and developmental psychology. The question of whether animals possess a ‘theory of mind’ occupies many researchers to this day, and forms a major focus in this special issue in the papers by Barrett et al. (2007), Clayton et al. (2007), Moll & Tomasello (2007) and Penn & Povinelli (2007).