Behavioural and Cultural Epigenetics. Social Biologisms Refuted by Developments in Biology

Developments in evolutionary studies, focused on the discovery of epigenetic inheritance and the social-environmental factors influencing it, have led to epochal turning points in the last three decades. Faced with these important changes, we can now consider the genocentric models that guided evolutionary studies from the last decades of the nineteenth century to the early ‘70s of the twentieth as obsolete. In fact, today we can demonstrate that, in the course of phylogenesis, at least three other kinds of selection, heredity and variation, respectively epigenetic, behavioural and cultural, operated alongside the slow processes of genetic variation, producing adaptive or maladaptive effects in a much more rapid way than that implicated by genetic mutations. Thanks to very young research areas such as behavioural and cultural epigenetics, we can now refute old and new social biologisms, ancient, ever re-emerging forms of biologistic determinism, with the tools of biology itself. We can indeed show that, through the methylation and demethylation processes, a lot of socio-environmental factors contribute to inhibit or re-activate gene expression, influencing fundamental aspects of an individual’s health, emotional, social and cognitive development with effects that are often transmitted to descendants for several generations. This essay discusses some of the most recent and representative results of these emergent areas of the epigenetic research and eco-evo-devo studies. This analysis reaches the conclusion that it is now anachronistic to hypothesize “human nature” being rigidly codified at the genetic level and substantially unchangeable in its fundamental mental and behavioural propensities.