The Strategies of the Genes: Genomic Conflicts, Attachment Theory, and Development of the Social Brain

Abstract

I describe and evaluate the hypothesis that effects of parent–offspring conflict and genomic imprinting on human neurodevelopment and behavior are central to evolved systems of mother–child attachment. The psychological constructs of Bowlby’s attachment theory provide phenomenological descriptions of how attachment orchestrates affective-cognitive development, and patterns of imprinted-gene expression and coexpression provide evidence of epigenetic and evolutionary underpinnings to human growth and neurodevelopment. Social-environmental perturbations to the development of normally secure attachment, and alterations to evolved systems of parent–offspring conflict and imprinted-gene effects, are expected to lead to specific forms of maladaptation, manifest in psychiatric conditions affecting social-brain development. In particular, underdevelopment of the social brain in autism may be mediated in part by mechanisms that lead to physically enhanced yet psychologically underdeveloped attachment to the mother, and affective-psychotic conditions, such as schizophrenia and depression, may be mediated in part by forms of insecure attachment and by increased relative effects of the maternal brain, both directly from mothers and via imprinted-gene effects in offspring. These hypotheses are concordant with findings from epidemiology, attachment theory, psychiatry, and genetic and epigenetic analyses of risk factors for autism and affective-psychotic conditions, they make novel predictions for explaining the causes of psychosis in Prader–Willi syndrome and idiopathic schizophrenia, and they suggest avenues for therapeutic interventions based on normalizing alterations to epigenetic networks and targeting public-health interventions toward reduction of perturbations to the development of secure attachment in early childhood and individuation during adolescence.