Epigenetics and the Evolution of Human Social Cognition

Human social cognitive abilities share derived attributes with other primates, but humans excel uniquely with regard to skills such as theory of mind, perspective-taking, sharing intentions and using language. Even these apparently unique abilities, however, must be supported by neurochemistry that is in turn developmentally dependent on genes derived from our primate lineage. In the last decade, epigenetic processes have emerged as an influence on differences both within and between mammalian species, and the brain is a major target for epigenetic processes regulating gene expression. This short review looks at how epigenetic processes may have contributed to human social cognitive evolution, how this relates to differences between human and non-human primate social cognition and to what extent this is consistent with the social brain hypothesis, i.e. increasing human sociality as a driver rather than a consequence of human brain evolution. The evidence ranges from general trends in maternally and paternally expressed genes influencing different parts of the brain, quantitative differences in mechanisms such as DNA methylation and gene expression in the brains of humans and other primates and examples of species-specific epigenetic regulation of genes associated with social cognition and language.