Do beliefs about aggressive feelings and actions predict reported levels of aggression?

In Study 1, a 40-item questionnaire measuring instrumental and expressive beliefs about aggression, along a five-point scale, was developed. It was based on a 20-item questionnaire (Campbell, Muncer & Coyle, 1992) where the two alternatives were forced choices for each item. In the present study the two sets of beliefs were only moderately correlated (-.35), and their separation into 20-item scales showed a clearer factor structure than combining all 40 items. Men showed higher instrumental scores whereas women showed higher expressive scores: factor analysis revealed one major factor in each case on which items showing the highest sex differences were concentrated. In Study 2 the questionnaire was used on another sample to assess the association between these beliefs and self-reported physical and verbal aggression, and anger. Instrumental beliefs were found to be highly correlated with physical aggression, and to a lesser extent verbal aggression. In this study, sex differences were similar to Study 1, but were complicated by the finding of stronger instrumental beliefs at younger ages for both sexes. In both studies, when filling out the questionnaire, women were equally likely to think of an aggressive episode with a same-sex opponent as with an opposite-sex partner whereas men nearly always thought of an aggressive episode with a same-sex opponent. However, neither instrumental nor expressive scores were affected by whether female respondents were thinking of a partner or same-sex other.