The interplay of genetic and environmental factors behind cognitive development has preoccupied multiple fields of science and sparked heated debates over the decades. Here we tested the hypothesis that developmental genes rely heavily on cognitive challenges - as opposed to natural maturation. Starting with a polygenic score (cogPGS) that…

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…

In this article, it is argued that it makes sense to define and distinguish three levels of human intelligence: intelligence as genotypical potential, intelligence as actualised in environmental interaction, and intelligence as measured by tests (IQ). This raises the questions of what is meant by the term "intelligence as potential", and…

This study tested implications of new genetic discoveries for understanding the association between parental investment and children's educational attainment. A novel design matched genetic data from 860 British mothers and their children with home-visit measures of parenting: the E-Risk Study. Three findings emerged. First, both mothers' and…

Background: Families of children with attention deficit hyperactivity disorder (ADHD) report more negative family relationships than families of children without ADHD. Questions remain as to the role of genetic factors underlying associations between family relationships and children's ADHD symptoms, and the role of children's ADHD…

In this paper we argue that moral behaviour is largely situation-specific. Genetic make-up, neurobiological factors, attachment security and rearing experiences have only limited influence on individual differences in moral performance. Moral behaviour does not develop in a linear and cumulative fashion and individual morality is not stable across…

Objective: To explain the differential course of anxiety and depression in individuals from childhood to adulthood by examining age-related changes in the genetic and environmental etiology of anxious and depressive symptoms. Method: A sample of 1470, 1839, and 2023 Dutch twins aged 12, 14, and 16 years reported on symptoms of anxious depression…

Environmental or genetic influences, or both could account for the increased risk of divorce among the offspring of separated parents. Previous studies have used covariates to statistically control for confounds, but the present research is the first genetically informed study of the topic. The investigation used the Children of Twins Design with…

A behavioral genetic analysis of general writing ability was conducted using teacher assessments based on UK National Curriculum criteria for a sample of 3296 same-sex pairs of 7-year-old twins. Writing was highly heritable within the normal range (0.66) and at the low extreme (0.70). Environmental influences were almost all non-shared, with…

This paper examines the links between childhood conduct disorder problems and schooling and labour market outcomes net of genetic and environmental effects. The results show that individuals who experienced conduct disorder problems are more likely to leave school early, have poorer employment prospects and lower earnings. These findings are shown…

The authors assessed 2,502 ten-year-old children, members of 1,251 pairs of twins, on a Web-based battery of problems from 5 diverse aspects of mathematics assessed as part of the U.K. national curriculum. This 1st genetic study into the etiology of variation in different domains of mathematics showed that the heritability estimates were moderate…

Hierarchical factor analyses involving Schmid-Leiman transformations were conducted on specific cognitive abilities data collected from 148 identical and 135 fraternal twin pairs from the Western Reserve Twin Project. Model fitting results reflect genetic influences on specific abilities and suggest that environmental influences are less…

This article considers the complications met by behavioral and biological studies of dyslexia by the condition's phenotypic heterogeneity and lack of uniformly applied diagnostic criteria. It notes the increasingly powerful genetic technologies and statistical methodologies used to identify genomic locations for genes involved in this complex…

Examines the interplay between genes and environment and argues that the development of much individual variation can be explained in terms of relatively simple forms of underlying regulation. Looks at "sensitive periods," during which variation is produced by experience received at a particular age. Includes a discussion of the…

In a study of 105 twin pairs, correlations for identical pairs were significantly higher than fraternal pairs on all but one factor: tough-mindedness. Data suggested several components and the total organization of those components of personality and temperament are genetically influenced. (Author)