Body dissatisfaction is a significant mental health symptom present in adolescent girls and boys. However, it is often either disregarded in adolescent boys or examined using assessments that may not resonate with males. The present study addresses these issues, examining the manifestation, etiology, and correlates of 3 facets of body…

Twin studies have documented that parenting behavior is partly heritable, but it is unclear how parents' genetics shape their caregiving. Using tools of molecular genetics, the present study investigated this process by testing hypotheses about associations between a genome-wide polygenic score for educational attainment and parental caregiving in…

The purpose of this study was to examine construct validity of methods of calculating lexical diversity in written narrative samples relative to children's performance on a reading vocabulary measure. For 234 children in first to fifth grade, written narratives were examined and compared between grades for number of different words (NDW), total…

The aim of this study was to disentangle pervasive from situational antisocial behaviors using multiple informants, and to investigate their genetic and environmental etiologies in preadolescence and across time. Antisocial behaviors were assessed in 2,232 twins from the Environmental Risk (E-Risk) Longitudinal Twin Study at ages 5 and 12.…

We document a largely unrecognized pathway through which schools promote human capital development -- by fostering informal mentoring relationships between students and school personnel. Using longitudinal data from a large, nationally representative sample of adolescents, we explore the frequency, nature, and consequences of school-based natural…

Purpose: The objective of this study was to compare children with persistent versus transient preschool language delay on language, academic, and psychosocial outcomes in elementary school. Method: Children with persistent language delay (n = 30), transient language delay (n = 29), and no language delay (controls; n = 163) were identified from a…

Parent depressive symptomatology is robust risk factor for externalizing behavior in childhood (Goodman et al., 2011). Although the precise mechanisms underlying this association have yet to be fully illuminated, there is some evidence that parent depression can impact externalizing behavior via both genetic and environmental pathways. In the…

Accurate understanding of environmental moderation of genetic influences is vital to advancing the science of cognitive development as well as for designing interventions. One widely-reported idea is increasing genetic influence on cognition for children raised in higher socioeconomic status families, including recent proposals that the pattern is…

Purpose: We evaluated genetic and environmental contributions to individual differences in language skills during early adolescence, measured by both language sampling and standardized tests, and examined the extent to which these genetic and environmental effects are stable across time. Purpose: We evaluated genetic and environmental…

Executive functions (EFs)--the higher level cognitive abilities that enable us to control our own thoughts and actions--continue to develop into early adulthood, yet no longitudinal study has examined their stability during the important life transition from late adolescence to young adulthood. In this twin study (total N = 840 individuals from…

This article bridges the literature on educational inequality between and within families to test whether high--socioeconomic status (SES) families compensate for low cognitive ability in the transition to secondary education in Germany. The German educational system of early-ability tracking (at age 10) represents a stringent setting for the…

At the end of compulsory schooling, young adults decide on educational and occupational trajectories that impact their subsequent employability, health and even life expectancy. To understand the antecedents to these decisions, we follow a new approach that considers genetic contributions, which have largely been ignored before. Using genomewide…

The Theory of Optimal Stimulation (Zentall & Zentall, "Psychological Bulletin," 94, 1983, 446) posits that the relation between activity level (AL) and cognitive performance follows an inverted U shape where midrange AL predicts better cognitive performance than AL at the extremes. We explored this by fitting linear and quadratic…

Purpose: Variability in the timing of infant developmental milestones is poorly understood. We used a twin analysis to estimate genetic and environmental influences on motor development and activity levels in infancy. Method: Data were from the Gemini Study, a twin birth cohort of 2,402 families with twins born in the United Kingdom in 2007.…

Identity formation is a key developmental task in adolescence. Although many adolescents in modern societies face issues of identity, there are substantial individual differences in identity exploration and commitment. Little is known about the origins of these individual differences. The current study investigated the genetic and environmental…