Negative Affect in the Relationship between Internalizing Symptoms and Aggression: The Role of Effortful Control

Although comorbidity is common between internalizing symptoms such as anxiety and depression and externalizing symptoms such as aggression, the reason for this co-occurrence remains unclear. High negative affect is one factor that has been proposed to explain the connection between anxiety and depression, as well as between these internalizing symptoms and externalizing symptoms including aggression; however, on its own, it may not explain the common association between symptoms. Research on anxiety suggests that effortful control moderates the relationship between negative affect and anxiety. Low levels of effortful control have also been tied to symptoms of depression and aggression. It was hypothesized that effortful control would moderate the impact of negative affect in associations between internalizing symptoms (anxiety and depression) and aggression such that individuals who have both high levels of negative affect and low levels of effortful control will be more likely to experience both internalizing symptoms and aggression. It was further proposed that, among the functional subtypes of aggression, this relationship would hold only for reactive aggression, and not for proactive aggression. These predictions were tested via hierarchical regression analyses of self-report data from a large sample of undergraduate students. Findings suggest that effortful control moderates the relationship between negative affect and depression; however, it functions as an additive predictor for both anxiety and reactive aggression. These findings and their implications are discussed.