Heritability of hostility-related emotions, attitudes, and behaviors.

Hostility-related variables have been categorized as to kinds of emotions, attitudes, and behaviors. Relatively few studies have explored whether genetic factors contribute to individual differences in these variables. Moreover, the majority of this research has involved male subjects. The present study utilized the twin method to evaluate the influence of genetic factors on hostility-related emotions, namely, trait anger and irritability, hostility-related attitudes, namely cynical hostility and suspiciousness, and hostility-related behaviors, namely, physical, verbal, and indirect aggression in adult women. Responses on the measure of trait anger showed evidence of significant heritability. However, evidence for a genetic component to responses on the irritability scale was less clear. There was no support for the notion of a genetic component to the measure of suspiciousness, and the evidence of a genetic contribution for cynical hostility was not significant. It was expected that due to environmental influences for women, only certain forms of aggression would show genetic variance, namely, verbal and indirect as opposed to physical forms. The results were generally congruent with these expectations.