Purpose: Researchers have previously shown that individual differences in measures of receptive language ability at age 12 are highly heritable. In the current study, the authors attempted to identify some of the genes responsible for the heritability of receptive language ability using a "genome-wide association" approach. Method: The…

Fourteen years ago, the first article on molecular genetics was published in this journal: "Child Development, Molecular Genetics, and What to Do With Genes Once They Are Found" (R. Plomin & M. Rutter, 1998). The goal of the article was to outline what developmentalists can do with genes once they are found. These new directions for developmental…

During childhood and adolescence, increases in heritability and decreases in shared environmental influences have typically been found for cognitive abilities. A sample of more than 2,500 pairs of twins from the Twins Early Development Study was used to investigate whether a similar pattern would be found for science performance from 9 to 12…

A previous finding from our group indicated that teacher-rated antisocial behaviour (AB) among 7-year-olds is particularly heritable in the presence of callous-unemotional (CU) traits. Using a sample of 1865 same-sex twin pairs, we employed DeFries-Fulker extremes analysis to investigate whether teacher-rated AB with/without CU traits also shows…

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…

Studied the genetic influence of low cognitive functioning in 200 pairs of twins aged at least 80 years and identified as not demented. Results suggest that the heritability of low cognitive functioning in this group was nonsignificant, but above-average cognitive functioning shows substantial group heritability. (SLD)

For DNA markers in or near genes of neurological relevance, allelic frequencies were compared for groups of high- and low-IQ children (total sample of 86). This study adds 40 markers to the 60 already studied. Only one showed a significant association with IQ in original and replication samples. (SLD)

Investigated genetic and environmental influences on the similarity and differences among five tests of cognitive abilities in 1,958 pairs of same-sex twins born in 1994 in the United Kingdom. Results suggest a developmental trend from modularity to molarity when considered in relation to multivariate genetic results later in life that show that…

Objective: To examine the etiologies of covariation of childhood sleep problems and other behavioral/emotional problems in young children. Method: The parents of more than 6,000 twin pairs provided information on their twins' anxiety, conduct, and hyperactivity at ages 3, 4, and 7 by completing the Strengths and Difficulties Questionnaire.…

Twin children were videotaped hitting an inflated clown figure. Three behaviors (number of hits, intensity of hits, and number of quadrants hit) showed adequate response characteristics, rater reliability, and test-retest reliability. Twin analyses of the three behavioral ratings yielded no evidence of hereditary influence. (Author)

The authors investigated the etiology of low mathematics performance in 7-year-olds in the context of normal variation. The lowest 15% were selected from a representative U.K. sample of 2,178 same-sex twin pairs rated by their teachers according to National Curriculum criteria in 3 domains of mathematics. Model-fitting analyses of mathematics…

Activity-level and childrearing questionnaires were administered to parents of 43 nursery school children. Results were interpreted as consistent with a heritable component to activity level. (ST)

Investigated genetic change and continuity within the domains of temperament, emotion, and cognition and language for 200 pairs of twins assessed at 14 and 20 months of age. Correlations of measures at the two ages indicated that individual differences in the second year of life showed greater change than continuity on most measures. (MDM)

A twin analysis was applied to infants' social behavior in standardized situations that permitted the comparison of social responding to mother and a stranger in different contexts. Twenty-one identical twin pairs and twenty-five fraternal twin pairs were observed in their homes using time-sampled observations of specific behaviors. (Author/SS)

The study of genotype-environment interaction (G x E) has been dominated by two competing hypotheses, one that heritability is greater in high-risk environments (diathesis-stress) and the other that heritability is greater in permissive environments. The current study examined relationships between verbal and nonverbal abilities and 10 measured…