Approach/Positive Anticipation,Frustration/Anger,and Overt Aggression in Childhood

ABSTRACT We examined mothers' ratings of children's affective and behavioral aspects of approach tendencies and links with overt aggressive behavior problems while considering the genetic etiology of these processes. Approach/positive anticipation (AP), frustration/anger (FA), and overt aggression in 4–9‐year‐olds were assessed using mothers' reports in a diverse national sample (n=992) and a sample of same‐sex twins (n=195 pairs). AP and FA were positively correlated with each other and with overt aggression (r from .2 to .5), and these associations were very similar for boys and girls. AP and FA provided overlapping as well as independent statistical prediction of aggression. AP statistical prediction of aggression was substantially mediated by FA, an effect that was accounted for by underlying genetic and nonshared environmental influences.     

A longitudinal behavioral genetic analysis of task persistence

Change in task persistence was assessed in two annual assessments using teachers', testers', and observers' ratings. Participants included 79 monozygotic and 116 same-sex dizygotic twin pairs who were in Kindergarten or 1st grade (4.3 to 7.9 years old) at the initial assessment. Task persistence was widely distributed and higher among older children and girls. Overall, there was modest growth in persistence over time, and moderate stability of individual differences. Most of the stability was accounted for by genetic influences, whereas most of the change was accounted for by nonshared environment, including an association with observed differential maternal warm supportive behavior.     

A cross-sectional behavioral genetic analysis of task persistence in the transition to middle childhood

Task persistence, measured by a composite score of independent teacher, tester and observer reports, was examined using behavioral genetic analysis. Participants included 92 monozygotic and 137 same-sex dizygotic twin pairs in Kindergarten or 1st grade (4.3 to 7.9 years old). Task persistence was widely distributed, higher among older children, positively associated with standardized tests of cognitive performance and achievement, and negatively associated with parents', teachers' and observers' reports of behavioral problems. Cross-sectional analysis indicated a strong developmental shift from shared environment variance among younger children to additive genetic variance in older children.