Psychopathy
Evolutionary explanations

Psychopathy is associated with several adverse life outcomes as well as increased risk of disability and death due to factors such as violence, accidents, homicides, and suicides. This, in combination with the evidence for genetic influences, is evolutionarily puzzling and may suggest that there are compensating evolutionary advantages, and researchers within evolutionary psychology have proposed several evolutionary explanations. According to one hypothesis, some traits associated with psychopathy may be socially adaptive, and psychopathy may be a frequency-dependent, socially parasitic strategy, which may work as long as there is a large population of altruistic and trusting individuals, relative to the population of psychopathic individuals, to be exploited. It is also suggested that some traits associated with psychopathy such as early, promiscuous, adulterous, and coercive sexuality may increase reproductive success. Robert Hare has stated that many psychopathic males have a pattern of mating with and quickly abandoning women, and thereby have a high fertility rate, resulting in children that may inherit a predisposition to psychopathy.

Criticism includes that it may be better to look at the contributing personality factors rather than treat psychopathy as a unitary concept due to poor testability. Furthermore, if psychopathy is caused by the combined effects of a very large number of adverse mutations then each mutation may have such a small effect that it escapes natural selection. The personality is thought to be influenced by a very large number of genes and may be disrupted by random mutations, and psychopathy may instead be a product of a high mutation load. Psychopathy has alternatively been suggested to be a spandrel, a byproduct, or side-effect, of the evolution of adaptive traits rather than an adaptation in itself.
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