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…

There is a growing body of opinion that we should view autism as fractionable into different, largely independent sets of clinical features. The alternative view is that autism is a coherent syndrome in which principal features of the disorder stand in intimate developmental relationship with each other. Studies of congenitally blind children…

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…

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…

This study was conducted to determine if a growing, urban school district was adequately addressing the academic, social-emotional and behavioral needs of students identified as homeless under the McKinney-Vento Act. McKinney-Vento eligible students were compared to non-homeless virtual twins. Each twin was created through averaging three…

This study was conducted to determine if a growing, urban school district was adequately addressing the academic, social-emotional and behavioral needs of students identified as homeless under the McKinney-Vento Act. McKinney-Vento eligible students were compared to non-homeless virtual twins. Each twin was created through averaging three…

This study was conducted to determine if a growing, urban school district was adequately addressing the academic, social-emotional and behavioral needs of students identified as homeless under the McKinney-Vento Act. McKinney-Vento eligible students were compared to non-homeless virtual twins. Each twin was created through averaging three…

This study examined (a) the predictive link between peer victimization and children's reactive and proactive aggression, and (b) the potential moderating effect of reciprocal friends' reactive and proactive aggression in this context. The study also examined whether these potential moderating effects of friends' characteristics were stronger with…

Objective: To study familial and nonfamilial environmental influences on attention problems and attention-deficit/hyperactivity disorder (ADHD) in monozygotic twins discordant and concordant-high and low for these traits. Method: Ninety-five twin pairs from The Netherlands Twin Register were selected. Longitudinal survey data were collected at 1,…

Objective: The purpose of this study was to assess heritability of activity, attention, and impulsivity by comparing young monozygotic (MZ) twins with dizygotic (DZ) twins using objective measures. Method: The OPTAx test is an infrared motion analysis to record the movement pattern during a continuous performance test. Seventeen MZ and 12 same…