Correction: A sequential model of the contribution of preschool fluid and crystallized cognitive abilities to later school achievement.

[This corrects the article DOI: 10.1371/journal.pone.

Genetic and phenotypic evidence of the predictive validity of preschool parent reports of hyperactivity/impulsivity and inattention.

To determine the validity of parent reports (PRs) of ADHD in preschoolers, we assessed hyperactivity/impulsivity (HI) and inattention (IN) in 1114 twins with PRs at 1.5, 2.5, 4, 5, 14, 15, and 17 years, and teacher-reports at 6, 7, 9, 10, and 12.

Continuity and change of genetic and environmental influences on reading and reading-related neurocognitive skills: A systematic review of longitudinal twin studies.

Learning to read is a dynamic and cumulative process beginning from birth and continuing through the school years. Empirical data showed a decrease of additive genetic (A) and shared environmental (C) components and an increase of non-shared environmental (E) components from preschool to middle school. However, our understanding of the aetiology of continuity and change of reading skills across this developmental period is limited.

Concurrent and prospective associations between family socioeconomic status, social support and salivary diurnal and hair cortisol in adolescence.

Background: Exposure to socioeconomic adversity is hypothesized to impact hypothalamic-pituitary-adrenal (HPA) axis activity and cortisol secretion, but existing evidence is inconsistent. Yet, few studies have investigated this association using a developmental approach that considers potential protective contextual factors. This study examined the role of stability and changes in family socioeconomic status (SES) in the prediction of multiple cortisol indicators and tested whether social support moderated these associations.

Adolescent anxiety and pain problems: A joint, genome-wide investigation and pathway-based analysis.

Both common pain and anxiety problems are widespread, debilitating and often begin in childhood-adolescence. Twin studies indicate that this co-occurrence is likely due to shared elements of risk, rather than reciprocal causation. A joint genome-wide investigation and pathway/network-based analysis of adolescent anxiety and pain problems can identify genetic pathways that subserve shared etiopathogenetic mechanisms.

Early temperamental and biological predictors of dimensions of social withdrawal in childhood.

Social wariness and preference for solitude, two dimensions of social withdrawal, show unique associations with various socioemotional difficulties in childhood, including internalizing and peer problems. However, their early childhood predictors remain vastly undocumented. The present study aimed to examine whether early indicators of reactivity in situations of unfamiliarity such as behavioral inhibition, affect, and cortisol independently, or in interaction with emotion regulation as indexed by vagal tone, predict later social wariness and preference for solitude.

A sequential model of the contribution of preschool fluid and crystallized cognitive abilities to later school achievement.

The present study documented in two distinct population-based samples the contribution of preschool fluid and crystallized cognitive abilities to school achievement in primary school and examined the mediating role of crystallized abilities in this sequence of predictive associations. In both samples, participants were assessed on the same cognitive abilities at 63 months (sample 1, n = 1072), and at 41 and 73 months (sample 2, n = 1583), and then with respect to their school achievement from grade 1 (7 years) to grade 6 (12 years). Preschool crystallized abilities were found to play a key role in predicting school achievement.

Uncovering the genetic architecture of broad antisocial behavior through a genome-wide association study meta-analysis.

Despite the substantial heritability of antisocial behavior (ASB), specific genetic variants robustly associated with the trait have not been identified. The present study by the Broad Antisocial Behavior Consortium (BroadABC) meta-analyzed data from 28 discovery samples (N = 85,359) and five independent replication samples (N = 8058) with genotypic data and broad measures of ASB. We identified the first significant genetic associations with broad ASB, involving common intronic variants in the forkhead box protein P2 (FOXP2) gene (lead SNP rs12536335, p = 6.

The Intensity of Formal Child-Care Attendance Decreases the Shared Environment Contribution to School Readiness: A Twin Study.

The purpose of this study was to explore if child-care intensity (hours/weeks) and age of onset could moderate genetic and environmental contributions to school readiness. A sample of 648 (85% Whites; 50% Females) pairs of twins was used to compute a GxE, CxE and ExE interaction analyses. The moderation model showed that shared environment explains 48% of individual differences in school readiness for children not attending formal child-care, and decreased gradually to a mere 3% for children attending formal child-care full time, e.

Link Between Peer Victimization in College and Cortisol Secretion: Roles of Genetic Vulnerabilities and Social Support.

It is unclear whether peer victimization in college interacts with genetic vulnerabilities or social support in predicting cortisol secretion. This issue was addressed using a sample of 162 Monozygotic and 237 Dizygotic twin pairs (54% females; 86% Whites, 6% Blacks, 6% Asians, 0.3% Native North Americans).

Classroom Placement and Twins' Social Behaviors in Elementary School: Providing Empirical Evidence to Inform Educational Policy.

Classroom placement of twins is an ongoing issue for educational policy. Many educational jurisdictions have standard policy most commonly founded in the belief that separation supports individual identity, personal development and academic opportunity. This study examined the effects of classroom placement in a sample of 560 twin pairs whose behaviors were assessed from ages 5 to 12 years.

Child Cognitive Flexibility and Maternal Control: A First Step toward Untangling Genetic and Environmental Contributions.

Executive functions (EF) play an essential role in many spheres of child development. Therefore, it is crucial to get a better understanding of their etiology. Using a genetic design that involved 934 twins (400 monozygotic), this study examined the etiology of cognitive flexibility, a component of EF, at 5 years of age and its phenotypic and etiological associations with maternal control.

Teachers' behaviour and children's academic achievement: Evidence of gene-environment interactions.

Background: Children's academic achievement is considerably influenced by genetic factors, which rarely operate independently of environmental influences such as teachers' behaviour. Praise and punitive discipline are commonly used management strategies by teachers. However, their effects on the genetic expression of children's academic achievement are still unclear.

Gene-Environment Interplay Linking Peer Victimization With Adolescents' Trajectories of Depressive Symptoms.

Objective: This study examined to what extent genetic and environmental factors explain-either additively or interactively with peer victimization-different trajectories of adolescents' depressive symptoms and whether genetic factors related to distinct trajectories are correlated with peer victimization.

Method: Participants included 902 twins (52% girls) who self-reported peer victimization and depressive symptoms in grades 6, 7, 8, 9, and 11.

Results: Growth mixture modeling revealed 3 trajectories of depressive symptoms: low (69.

Changing genetic architecture of body mass index from infancy to early adulthood: an individual based pooled analysis of 25 twin cohorts.

Background: Body mass index (BMI) shows strong continuity over childhood and adolescence and high childhood BMI is the strongest predictor of adult obesity. Genetic factors strongly contribute to this continuity, but it is still poorly known how their contribution changes over childhood and adolescence. Thus, we used the genetic twin design to estimate the genetic correlations of BMI from infancy to adulthood and compared them to the genetic correlations of height.

Association between the timing of family socioeconomic deprivation and adolescence hair cortisol among adolescent twins: A study of the genetic and environmental processes involved.

Background: While evidence shows that lower socioeconomic status (SES) is related to dysregulated hair cortisol concentration (HCC), the genetic and environmental processes underlying this association remain understudied.

Objectives: (1) to examine whether childhood and adolescence SES are phenotypically related to late adolescence HCC and to what extent these associations are explained by common underlying genetic factors (2) to estimate whether the genetic and environmental etiology of HCC varies according to SES and the timing of these experiences.

Methods: Participants were 422 twin pairs for whom SES was measured in childhood (ages 0-5 years) and adolescence (age 14 years).

The gene environment aetiology of freezing and its relationship with internalizing symptoms during adolescence.

Background: The freezing response is a universal response to threat, linked to attentive immobility and action preparation. It is relevant for acute stress coping in animals and humans, and subtle deviations in toddler freezing duration (absence of, or excessively long reactions) have been linked to higher risk for internalizing symptoms in adolescence. Yet, while individual freezing tendencies are relatively stable throughout life, little is known about their gene-environment aetiology.

From preschool language skills to writing in adolescence: Evidence of genetic continuity.

Given the importance of writing for academic achievement, this study aimed to understand how early oral language contributes to later writing skills. The first objective was to determine if preschool language skills were associated with high school writing, and if so, whether they contributed directly or indirectly through school age language. The second aim was to explore the extent to which genetic and environmental factors explained these potential associations.

Maternal depressive symptoms and children's cognitive school readiness: the role of gene-environment interplay.

Maternal depressive symptoms are a robust risk factor for poor cognitive outcomes in children, yet the role of gene-environment interplay in this association is not well understood. The objective of this study was to evaluate gene-environment interaction in the association between maternal depressive symptoms and children's cognitive school readiness. Data come from a population-based birth cohort of 538 twin pairs.

A multi-informant and multi-polygenic approach to understanding predictors of peer victimisation in childhood and adolescence.

Introduction: Peer victimisation is a prevalent occurrence in childhood and adolescence and can often have long-lasting consequences. Previous research using polygenic scores (PGSs) have revealed various genetic vulnerabilities as predictive of victimisation in childhood. However, findings were based on self-report and may therefore be influenced by varying self-perceptions.

Adolescent pain: appraisal of the construct and trajectory prediction-by-symptom between age 12 and 17 years in a Canadian twin birth cohort.

Adolescent pain is common and continues into adulthood, leading to negative long-term outcomes including substance-related morbidity: an empirical definition of its construct may inform the early detection of persistent pain trajectories. These secondary analyses of a classical twin study assessed whether headaches, back pains, abdominal pain, chest pains, stabbing/throbbing pain, and gastric pain/nausea, measured in 501 pairs across 5 waves between age 12 and 17 years, fit a unitary construct or constitute independent manifestations. We then assessed which symptoms were associated with a steady, "frequent pain" trajectory that is associated with risk for early opioid prescriptions.

A genetically-controlled, cross-lagged study of the association between friends' deviance and participants' delinquency during adolescence: A replication.

The goal of the present study was to replicate Burt et al. (2009) and Hou et al. (2013) findings by determining the contribution of peers' deviance to changes in participants' (monozygotic [MZ] twins') self-reported delinquency from mid- to late adolescence while controlling for possible gene-environment correlations (rGE) through the use of the cotwin method in the context of a cross-lagged design.

Unique and interactive associations of proactive and reactive aggression with cortisol secretion.

The association between aggressive behaviors and diurnal cortisol levels has been debated over the past two decades, as some studies found a negative link between the two, whereas others reported no or a positive association. One possible explanation for these contradictory results is that past studies failed to distinguish between proactive (PROA) and reactive (REA) aggression. The present study examined the unique and joint associations of PROA and REA with three diurnal cortisol indicators: awakening levels, awakening response, and diurnal change.

Links between peer victimization, dating violence victimization and depression in adolescence: A genetically-informed study.

Objective: The current study aimed to test if individuals with inherent dispositions to depression-related cognitions and behaviors are more at risk of experiencing relational difficulties, such as peer victimization and dating violence victimization.

Method: This study used a genetically informed design with 806 twins (51.5% girls) to test 1) if at least part of the association between peer victimization in school and dating violence victimization in emerging adulthood can be explained by common underlying heritable factors.

The phenotypic associations and gene-environment underpinnings of socioeconomic status and diurnal cortisol secretion in adolescence.

While converging evidence suggests that both environmental and genetic factors underlie variations in diurnal cortisol, the extent to which these sources of influence vary according to socioeconomic status (SES) has seldom been investigated, particularly in adolescence. To investigate whether a distinct genetic and environmental contribution to youth's diurnal cortisol secretion emerges according to family SES and whether the timing of these experiences matters. Participants were 592 twin pairs, who mostly came from middle-income and intact families and for whom SES was measured in childhood and adolescence.