Despite the importance of self-control for well-being and adjustment, its development from early childhood to early adolescence has been relatively understudied. We addressed the development of mother-reported self-control in what is likely the largest and longest longitudinal twin study of the topic to this day (N = 1889 individual children with…

Previous research has attempted to understand why countries with relatively favorable conditions and high estimated average IQs (such as Finland and Japan) have a relatively low per capita number of scientific Nobel prizes. In the present study, we examine whether there is a relationship between national schizophrenia and left-handedness…

The non-cognitive skills self-control and grit are often considered predictors of school performance, but whether this relationship is causal remains unclear. We investigated the causality of this association using a twin design. Specifically, we evaluated the direct impact of self-control and grit on school performance, while controlling for…

Sleep is important for child development. Sleep problems in early childhood are associated with negative outcomes across numerous domains, including executive control, internalizing and externalizing psychopathology, and social competence (Astill et al., 2012; Hysing et al., 2016; Spruyt et al., 2019). Little research has focused on moderators…

Broader autism phenotype (BAP) characteristics (pragmatic language deficits, aloofness, and rigidity) are prevalent in families of individuals with autism spectrum disorder (ASD) and may influence emotion-related behaviors. The current study analyzed associations among BAP characteristics with emotion-related behaviors in mothers of children with…

Emerging research suggests that caregiving environments and genetic variants independently contribute to social functioning in children with typical development or autism spectrum disorder (ASD). However, biologically plausible interactive models and complimentary assessment of mechanisms are needed to: (1) explain considerable social…

Background: Research suggest that genetic testing and its application (personalized medicine/precision medicine) has great potential to help public health professionals deliver proper health promotion and education to target populations who have high predispositions for certain genetic-related diseases. Purpose: The purpose of this study was to…

Epigenetic regulation of the placental glucocorticoid receptor gene ("NR3C1") was investigated as a mechanism underlying links between maternal smoking during pregnancy (MSDP) and infant neurobehavior in 45 mother-infant pairs (49% MSDP-exposed; 52% minorities; ages 18-35). The Neonatal Intensive Care Unit (NICU) Network Neurobehavioral…

According to Lev S. Vygotsky (1896-1934), the highest levels of abstract thinking and self-regulation in preschool development are established in "pretend play using object substitutions." An extensive research literature supports Vygotsky's empirical model of the internalization of self-guiding speech (social speech > private speech…

Twin factor mixture modeling was used to identify temperament profiles while simultaneously estimating a latent factor model for each profile with a sample of 787 twin pairs (M[subscript age] = 7.4 years, SD = 0.84; 49% female; 88.3% Caucasian), using mother- and father-reported temperament. A four-profile, one-factor model fit the data well.…

ADHD is a disability characterised by hyperactivity, impulsivity and difficulties maintaining attention. Despite extensive research on ADHD, the effects of existing treatments are moderate and inconsistent. Knowledge regarding children's and adolescents' everyday experiences of Attention Deficit Hyperactivity Disorder (ADHD) and their…

Background: Evocative gene-environment correlation (rGE) describes a process through which children's heritable characteristics influence their rearing environments. The current study examined if heritable influences on parenting and children's behavioral outcomes operate through child negative emotionality. Method: Using data from the Early…

Social-emotional behavior in autism spectrum disorder (ASD) was examined among high-risk (HR; siblings of children diagnosed with ASD) and low-risk (LR; no family history of ASD) toddlers. Caregivers completed the Infant-Toddler Social Emotional Assessment (ITSEA) at 18 months, and blind diagnostic assessment for ASD was conducted at 36 months.…

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…

Children with autism spectrum disorder often demonstrate difficulties with self-regulation, although studies of this construct in young children with autism spectrum disorder are limited. In this study, developmental changes were examined using a measure of self-regulation appropriate for young children, resistance to temptation. At 22, 28, and 34…