Results of twin factor models at age 14 and 17.

Instruments for rating socioemotional behavior with a strong theoretical basis, broad coverage of behaviors, and adequate validation are rare. Here, the Multidimensional Peer Nomination Inventory (MPNI) Form SERI (Socio(E]motional Regulation Inventory) was employed in a longitudinal population-based sample of Finnish twins at age 17 to study: (1) the structure of self-ratings on self-regulation of socioemotional behavior, (2) construct, criterion, concurrent, and predictive validity of the scales, as well as invariance analysis, and (3) genetic and environmental factors contributing to individual differences in self-regulation. A bipolar factor for low versus high self-regulation was interpreted as representing vulnerability to a p-factor (general psychopathology) versus src-factor (self-regulation capacity), and respective scales were formed for both. Behavioral regulation in each was further categorized into a Problem behavior scale (comprising subscales for Hyperactive/Inattentive, Aggressive, and Anxious behavior) and a Prosocial behavior scale. Self-ratings on these scales had high correlations with co-twin ratings at age 17 and similarly formed scales for self- and co-twin ratings at age 14. Twin modeling indicated that the p-factor and src-factor are moderately heritable and attributable to both genetic and unique environmental influences. The inventory can be used for self- and sibling ratings in population studies.