Affective Contributions to Instrumental and Reactive Aggression in Middle Childhood: Variable- and Person-Centered Approaches.

Objective: Research on the role of affect in childhood aggression motives has largely focused on domain-level affective traits. Lower-order affective facets may show more distinct relationships with instrumental and reactive aggression - at both the variable and individual levels - and offer unique insights into whether and how several forms of affect are involved in aggression motives.

Method: Caregivers (98% mothers) of 342 children (M_age = 9.81 years, 182 girls, 31% White) reported on children's aggression and affect-relevant personality traits, personality pathology, and callous-unemotional traits.

Results: Both reactive and instrumental aggressions were characterized by higher levels of trait irritability, fear, withdrawal, sadness, and callous-unemotional traits in zero-order analyses. Instrumental aggression was characterized by low trait positive emotions. Reactive aggression was uniquely associated with irritability, fear, withdrawal, and sadness, whereas instrumental aggression was uniquely associated with callous-unemotional traits and (low) positive emotions. Groups identified by latent profile analyses were differentiated only by aggression severity.

Conclusions: The findings support both the similarity and distinction of reactive and instrumental aggression vis-à-vis their affective phenomenology. Consistent with existing theories, reactive aggression was linked to multiple forms of negative emotionality, whereas instrumental aggression was linked to higher levels of callous-unemotional traits. In a novel finding, instrumental aggression was uniquely characterized by lower positive emotions. The findings highlight the utility of pre-registered approaches employing comprehensive personality-based affective frameworks to organize and understand similarities and differences between aggression functions.