Contribution of temperament to eating disorder symptoms in emerging adulthood: Additive and interactive effects.

Temperament characteristics, such as higher negative emotionality (NE) and lower effortful control (EC), are individual difference risk factors for developmental psychopathology. Research has also noted relations between temperament and more specific manifestations of psychopathology, such as eating disorders (EDs). Although work is emerging that indicates that NE and EC may additively contribute to risk for ED symptoms, no studies have considered the interactive effects of NE and EC in relation to ED symptoms. In the current investigation, we hypothesized that (1) low EC would be associated with increased ED symptoms, (2) high NE would be associated with increased ED symptoms, and (3) these temperament traits would interact, such that the relationship between NE and ED symptoms would be strongest in the presence of low EC. After controlling for gender and child trauma history, emerging adults' (N=160) lower EC (i.e., more difficulties with self-regulation) was associated with more ED symptoms. NE did not emerge as a direct predictor of ED symptoms. However, the anticipated interaction of these temperament characteristics on ED symptoms was found. The association between NE and ED symptoms was only significant in the context of low EC. These findings provide evidence that elevated NE may only be a risk factor for the development of eating disorders when individuals also have self-regulation difficulties. The implications of these findings for research and interventions are discussed.