This study examined the mediating role of emotional availability in the relation between parent positive personality and toddler problem behavior. The sample comprised 654 twins at 12 and 32 months. Primary caregivers (>95% mothers) completed six measures indexing parent positive personality assessed at 12 months, and emotional availability and…

There is considerable variability in the extent to which young people with developmental language disorder (DLD) experience mental health difficulties. What drives these individual differences remains unclear. In the current article, data from the Twin Early Development Study were used to investigate the genetic and environmental influences on…

This investigation examines the spread of problem behaviors (substance use and delinquency) between twin siblings. A sample of 628 twins (151 male twin pairs and 163 female twin pairs) drawn from the Quebec Newborn Twin Study completed inventories describing delinquency and substance use at ages 13, 14, and 15. A 3-wave longitudinal actor-partner…

This study used a genetically controlled design to examine the direction and the magnitude of effects in the over-time associations between perceived relationship quality with mothers and adolescent maladjustment (i.e., depressive symptoms and delinquency). A total of 163 monozygotic (MZ) twins pairs (85 female pairs, 78 male pairs) completed…

Background: Childhood behavior problems predict subsequent educational achievement; however, little research has examined the etiology of these links using a longitudinal twin design. Moreover, it is unknown whether genetic and environmental innovations provide incremental prediction for educational achievement from childhood to adolescence.…

Background: The behavioural symptoms of autism spectrum disorder (ASD) are thought to reflect underlying cognitive deficits/differences. The findings in the literature are somewhat mixed regarding the cognitive features of ASD. This study attempted to address this issue by investigating a range of cognitive deficits and the prevalence of multiple…

Drawing on a sample of twin children from the Early Childhood Longitudinal Study, Birth Cohort (ECLS-B; Snow et al., 2009), the current study analyzed 2 of the most prominent predictors of externalizing behavioral problems (EBP) in children: (a) parental use of spankings and (b) childhood self-regulation. A variety of statistical techniques were…

Adolescence and early adulthood is a time when peer groups become increasingly influential in the lives of young people. Youths exposed to deviant peers risk susceptibility to externalizing behaviors and related psychopathology. In addition to environmental correlates of deviant peer affiliation, a growing body of evidence has suggested that…

A body of empirical research has revealed that there are associations among language skills, peer interactions, and behavioral problems in childhood. At the same time, however, there has been comparatively less research devoted to exploring the mutual unfolding of these factors over the first few years of life. The current study is designed to…

Early attachment has both protective and risk factors as regards later mental health. In Finland, insecure-avoidant-type attachment is overrepresented. Does this indicate a risk for emotional and behavioural problems at preschool age? In this study, we examined and compared the association between attachment and mental health in Finnish singletons…

Parents' expectations for their children's ultimate educational attainment have been hypothesized to play an instrumental role in socializing academically relevant child behaviors, beliefs, and abilities. In addition to social transmission of educationally relevant values from parents to children, parental expectations and child…

Using both traditional composites and novel profiles of anger, we examined associations between infant anger and preschool behavior problems in a large, longitudinal data set (N = 966). We also tested the role of life stress as a moderator of the link between early anger and the development of behavior problems. Although traditional measures of…

There has been significant interest in examining the developmental factors that predispose individuals to chronic criminal offending. This body of research has identified some social-environmental risk factors as potentially important. At the same time, the research producing these results has generally failed to employ genetically sensitive…

Background: Preschool involves an array of new social experiences that may impact the development of early externalizing behavior problems over the transition to grade school. Methods: Using longitudinal data from a nationally representative sample of over 600 pairs of US twins, we tested whether the genetic and environmental influences on…

Research on sex differences in antisocial behaviour may shed light on the causes of childhood antisocial behaviour. Using a longitudinal design, we tested whether there were sex differences in the amount of harsh discipline children received or in the effect of harsh discipline and whether this accounted for sex differences in later conduct…