Parasite stress promotes homicide and child maltreatment

Abstract

Researchers using the parasite-stress theory of human values have discovered many cross-cultural behavioural patterns that inform a range of scholarly disciplines. Here, we apply the theory to major categories of interpersonal violence, and the empirical findings are supportive. We hypothesize that the collectivism evoked by high parasite stress is a cause of adult-on-adult interpersonal violence. Across the US states, parasite stress and collectivism each positively predicts rates of men's and women's slaying of a romantic partner, as well as the rate of male-honour homicide and of the motivationally similar felony-related homicide. Of these four types of homicide, wealth inequality has an independent effect only on rates of male-honour and felony-related homicide. Parasite stress and collectivism also positively predict cross-national homicide rates. Child maltreatment by caretakers is caused, in part, by divestment in offspring of low phenotypic quality, and high parasite stress produces more such offspring than low parasite stress. Rates of each of two categories of the child maltreatment-lethal and non-lethal-across the US states are predicted positively by parasite stress, with wealth inequality and collectivism having limited effects. Parasite stress may be the strongest predictor of interpersonal violence to date.

Violence, Teenage Pregnancy, and Life History

“…Pathogen sensitivity may also be important. Data show that levels of disease prevalence are related to violent behaviours toward partners and children (Thornhill & Fincher, 2011) and to measures of sociosexuality (Schaller & Murray, 2008). Evolved pathogen sensitivities may therefore play a part in mortality assays.…”

What Can Cross-Cultural Correlations Teach Us about Human Nature?

“…For instance, Thornhill and Fincher (2011) show that U.S. states with higher estimated levels of parasite stress have higher rates of romantic partner murder, homicide, and male-honor homicide. From these patterns, the authors infer that exposure to parasites during development (i.e., parasite stress) has a causal effect on individuals' propensity for violence.…”

“…1). Investigations using these techniques have addressed topics such as the effects of ecological pathogen stress on crime, values, and cognitive ability (e.g., Cashdan and Steele 2013;Eppig et al 2010;Hackman and Hruschka 2013;Shrira et al 2013;Thornhill and Fincher 2011), parent-offspring conflict over mate choice (e.g., Apostolou 2010), sex ratios (both operational and offspring sex ratios: e.g., Barber 2000; Dama 2011Dama , 2012Dama , 2013Kruger and Nesse 2006;Kruger and Schlemmer 2009;Thomas et al 2013), mate preferences (e.g., DeBruine et al 2010;DeBruine et al 2011;Moore et al 2013), pair bonding (e.g., Quinlan and Quinlan 2008), parental investment (e.g., Barber 2003;Marlowe 2003), homosexual preferences (Barthes et al 2013), personality (e.g., Schmitt et al 2008), economic decision-making (e.g., Marlowe et al 2008Marlowe et al , 2011, and sexual dimorphism (Wells 2012). Fig.…”

Moral concerns across the United States: associations with life-history variables, pathogen prevalence, urbanization, cognitive ability, and social class

“…Specifically, when controlling for teenage birth rate and ethnicity as measures of faster life-history strategy and extrinsic risk, respectively, pathogen prevalence no longer predicted variation in homicide, child abuse, and strength of family ties across states (cf. Fincher & Thornhill, 2012;Thornhill & Fincher, 2011). Faster life-history strategy is expected to be associated with higher teenage birth rate and shorter life expectancy.…”