Developmental and mating preference differences in primary and secondary psychopathy

There is a long-standing debate regarding developmental differences in primary and secondary psychopathy, and what these differences say in terms of their evolutionary origins. Although both are thought to be fast life history strategies that are adaptive in harsh and unpredictable environments, primary psychopathy is thought to have a genetic basis, while secondary psychopathy is thought to be caused by environmental factors. The aim of the thesis was to contribute further to the debate by investigating hitherto unexamined factors in the development of primary and secondary psychopathy using a Life History, Parental Investment Theory perspective. Specifically, whether quality of parental bonding, quality of attachment in close relationships, and fetal programming (pertaining to prenatal testosterone exposure) differed between men and women high in primary or secondary psychopathy. The contribution of prenatal testosterone to callous unemotional traits and externalising behaviours in children was also examined. Furthermore, as putative adaptive personality types, the attractiveness of primary or secondary psychopathy in partners to heterosexual men and women high or low in primary or secondary for short and long-term mating was investigated. The thesis consists of four studies that utilised a series of questionnaires, the 2D:4D digit ratio and vignettes measured in non-clinical samples: Chapter 2 explored differences between men and women high in primary or secondary psychopathy in recollections of how cold and controlling their parents were during childhood alongside attachment style in adulthood. Primary psychopathy in men was associated with avoidant attachment and uncaring mothers, while in women it was related to uncaring fathers and anxious and avoidant attachment. Secondary psychopathy in men related to uncaring mothers and fathers, while in women it was not related to parental bonding quality or either attachment type. Chapter 3 examined the quality of maternal bonding and exposure to prenatal testosterone (2D:4D ratio) as influences in the development of primary or secondary psychopathy between men and women. The findings re-confirmed differences between sex and psychopathy variants. Chapter 4 investigated the effects of exposure to higher levels of prenatal testosterone (2D:4D ratio) on callous unemotional traits (CU) and externalising behaviour in children aged 5-6 years old. CU traits were found to moderate the relationship between prenatal testosterone and externalising behaviour. Chapter 5 explores the attractiveness and mating preferences of men and women high or low in primary or secondary psychopathy for short and long term relationships. Men high in primary or secondary psychopathy did not discriminate in mate choice in either relationship context, however women high in primary or secondary psychopathy preferred their opposite sex equivalents in short and long-term relationships. Men and women low in primary or secondary psychopathy preferred partners equivalent to them in psychopathy regardless of relationship length. In summary, the results of this thesis demonstrate differences in psychopathy variants between men and women, as well as in children, further highlighting contrasts in genetic and environmental contributions to primary and secondary psychopathy. Moreover, the variations between men and women high in primary or secondary psychopathy appear to function according to inequity in parental investment which also informs their mating preferences in short and long term mating.