Children of 18 months classified as secure or insecure/avoidant by means of the Ainsworth Strange Situation were observed at home and in a playgroup. Teachers and observers rated girls classified as insecure/avoidant as being more difficult to deal with and having more difficulty with peers than girls rated as securely attached. (PCB)

Relations among hormone levels, emotional dispositions, and aggressive attributes were examined in 56 boys and 52 girls, aged 9 to 14 years. (PCB)

Examined factors associated with young children's aggression. Observed 104 toddlers during free play with same-sex peer, with both mothers present. Found that early out-of-home care was not related to aggression. Boys were more aggressive than girls. Observed aggression and mother-reported externalizing problems were associated significantly with…

Parents of Swedish twin pairs ages 7 to 9 years and of British twin pairs ages 8 to 16 years completed the Child Behavior Checklist. Found that genetic factors influenced aggressive antisocial behavior to a greater extent than nonaggressive antisocial behavior, which was also significantly influenced by the shared environment. There was a…

Assessed impact of an antipoverty program on family functioning and developmental outcomes for preschool- and school-aged children. Found that the New Hope program had strong positive effects on boys' academic achievement, classroom behavior, positive social behavior, and problem behaviors, and on boys' expectations for advanced education and…

Examined the nature of teacher responses to preschoolers' problem and preacademic behavior as a function of sex. Teachers generally responded more frequently to boys. (ST)

Insecurely attached boys were less liked by peers and teachers; were perceived as more aggressive by classmates; and were rated by teachers as less competent and as having more behavior problems than were secure boys. No such association emerged for girls. Participants were 89 children assessed before and after they entered first grade and their…

Examined the influence of friends' behaviors and the features of their friendships on 297 adolescents' school adjustment. Found that students whose friends described themselves as more disruptive increased in self-reported disruption over the course of the school year. Girls' self-reported disruption was more influenced by that of their best…

Examined multiple measures of 82 young children's emotionality, regulation, and social functioning over a 2-year period, finding that social functioning was predicted by low negative emotionality and high levels of regulation. Also found that vagal tone was positively related to competent social functioning and emotionality/regulation for boys,…

Examined the relationship between 41 preschool children's peer competency and the exchange of reciprocal negative affect displays during physical play with parents. Found that fathers who typically responded to their children's negative affect displays with negative affect of their own had children who shared less, were more aggressive, and…

Examined mother-child interaction predictors of initial levels and changes in child aggressive and disruptive behavior at school from kindergarten to third grade in 585 mother-child dyads. Found that for boys, high coercion and nonaffection were particularly associated with the high-increasing-aggression trajectory, but for girls, high levels of…

Assessed child behavior, maternal depression, and family socioeconomic status and observed mother-child interactions for 376 first graders and their mothers. Found that the quality of mother-child interactions mediated the relationship between maternal depression and child behavior problems for boys, girls, and Caucasians but not for African…

Explored aggression and delinquency in unrelated adoptive sibling pairs and biologically-related sibling pairs in the Colorado Adoption Project at 7, 9, 10, 11, and 12 years. Found that boys and adopted children were higher in externalizing behavior problems than girls and biologically related pairs. Sex differences in delinquency were more…

Examined within-family differences in parenting and problem behavior in 95 nondivorced and 421 remarried families. Within-family differences in parenting and problem behavior were greatest in remarried families where siblings did not share the same biological parent. Differential treatment was also more strongly related to problem behavior in this…