Genetic evidence that Darwin was right about criminality: Nature, not nurture

SummaryDarwin maintained that man’s behaviours, just as the ones of the lower animals, are not cultural products of learning, but constitute evolutionarily selected innate traits that can be transmitted through biological inheritance. Coherently, Darwin wrote that “some elimination of the worst dispositions is always in progress … Malefactors are executed … so that they cannot freely transmit their bad qualities”. Darwin’s evolutionary deterministic views about the innateness of human behaviours and the heritability of criminal tendencies proved genially farsighted. Indeed, the scientific evidence that they are genetically determined became indisputable just in this century, about 120 years after Darwin’s death. This article, besides discussing human genetic variation and the genetic basis of pro-social traits, focuses on the recent and mounting evidence that points to genes for antisocial behaviours, genes for criminality, and genes for violence. All of them contribute to discredit further the scientifically untenable cultural dogma claiming that human behaviours reflect nurture, represented by social environments, not nature, in the form of biological factors. Genes for criminality and violence also concur to demolish the ideological dogma espoused by those who assert that criminality is a result of poverty and unemployment. The falsity of that politically biased dogma, as argued in this article, is also demonstrated by the fact that Brazil, despite significant reductions of poverty, socioeconomic disparities, and unemployment during the last five years, is facing a spiralling increase in criminal misdeeds, including homicides, which have reached an alarming rate that is nearly fivefold higher than the already worrying one of the USA.