Complex Relations Between Psychopathy and Fitness May Indicate Adaptive Trade-Offs

Abstract

In order to assess the potential of psychopathy to increase evolutionary fitness, we examined the relations between psychopathy and fitness indicators (number of children and grandchildren, problems in physical health both in parents and offspring) in a sample of post-reproductive individuals (N = 187; Mage = 66.52). Specifically, we explored the possibility that psychopathy traits are involved in evolutionary trade-offs: both positive and negative relations with different fitness components. Psychopathy was measured via three traits—interpersonal, affective, and lifestyle characteristics, which are operationalized by proxy scales derived from the HEXACO-PI-R inventory. Research findings showed that interpersonal traits were positively related to the number of children and negatively to the number of grandchildren and problems in physical health; lifestyle characteristics were positively associated with problems in physical health in participants’ offspring. The data are in line with previous studies which explored the relations between psychopathy and fitness. The findings extend on previous studies by suggesting that psychopathy may be involved in evolutionary trade-offs, especially the quantity-quality trade-off. These trade-offs may in return maintain inter-individual variation in psychopathy.