Focquaert, F. & Braeckman, J. (2011). Mirroring the mind: on empathy and autism. A. De Block, & P. Adriaens (Eds.). Maladapting minds (pp. 241-263). Oxford University Press.

From an evolutionary point of view, the prevalence of disorders that are characterized by (extremely) low-empathy, such as autism spectrum conditions and psychopathy, is hard to grasp. Empathy affects almost every aspect of our social world ans (extremely) low empathizing skills are devastating to an individual's social life. The following questions loom large: Why are autism spectrum conditions so common and why are they more prevalent in men? And in general, why does a 'negative' trait like low empathy even manifest itself at all? Keller and Miller's mutational load model, that describes mental disorders in terms of an 'overload' of harmful mutations, is put forward to explain more extreme instances of autism. Less extreme instances of autism spectrum disorders are explained by the presence of maladaptive extremes of low empathy in combination with compensatory systemizing mechanisms. Based upon existing evolutionary hypotheses and current (neuro) cognitive findings, we propose that high empathy, with a 'high' threshold to shut down, is more likely to have evolved during female evolutionary history. Low(er) empathy, with a low threshold to 'shut down', is more likely to have evolved during male evolutionary hisory. Differrential selection pressures on empathy may therefore explain the male/female ratio in autism spectrum conditions, and possibly, a difference in empathy between males and females in general.