In this paper we assess the presence of assortative mating, gene-environment interaction and the heritability of intelligence in childhood using a twin family design with twins, their siblings and parents from 112 families. We evaluate two competing hypotheses about the cause of assortative mating in intelligence: social homogamy and phenotypic…

The classical twin study provides a useful resource for testing hypotheses about how the family environment influences children's development, including how genes can influence sensitivity to environmental effects. However, existing statistical models do not account for the possibility that children can inherit exposure to family environments…

Comments on the article by E. Diener, R. E. Lucas, and C. N. Scollon (see record 2006-05893-003) which cited a study by Tellegen et al. in which the Well-Being scale of the Multidimensional Personality Questionnaire (MPQ), administered to 44 pairs of monozygotic reared-apart (MZA) twins, yielded a within-pair correlation of 0.48. I contend that,…

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…

We examined the genetic and environmental contribution to the stability and instability of reading outcomes in early elementary school using a sample of 283 twin pairs drawn from the Western Reserve Reading Project. Twins were assessed across two measurement occasions. In Wave 1, children were either in kindergarten or first grade. Wave 2…

Genetic concepts have significantly evolved over the last ten years, and are now less connected to innate ideas and reductionism. Unique reference to genetic determinism has been replaced by the interaction between the genes and their environment (epigenetics). Our analyses relate to how current school biology textbooks present this new paradigm…

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…

The genetic and environmental etiologies of 3 aspects of low mathematical performance (math disability) and the full range of variability (math ability) were compared for boys and girls in a sample of 5,348 children age 10 years (members of 2,674 pairs of same-sex and opposite-sex twins) from the United Kingdom (UK). The measures, which we…

Anxiety and conduct problems covary, yet studies have not explored the genetic and environmental origins of this association. We analyzed parent-reported anxiety and conduct problems in 6,783 pairs of twins at 2-, 3-, and 4-years of age. As anxiety and conduct problems were fairly stable across the three ages (average 1-year correlation was .53),…

Although prior research has examined children's perceptions of the classroom environment as related to academic achievement, genetically sensitive designs have not been employed. In the first study of its kind for the primary school classroom environment, data were collected for 3,020 pairs of nine-year-old identical and fraternal twin pairs in…

Reviews genetic influence on suicide. Reviews methodologies for studying the nature-nurture issue and examines their applicability to the study of suicide. Reviews research from the methodologically sound strategies. Examines work by Uematsu using an approach different from any of the conventional methodologies. (Author/ABB)

Presents interview with Thomas Bouchard, a leading researcher of identical twins reared apart. Describes major themes in the Minnesota twin research. Claims, although genetic influence is central, Bouchard pleas for the impact of environmental factors in optimal human development. Includes Bouchard's surprising experiences, current focus, and…

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…

Change in task persistence was assessed in two annual assessments using teachers', testers', and observers' ratings. Participants included 79 monozygotic and 116 same-sex dizygotic twin pairs who were in Kindergarten or 1st grade (4.3 to 7.9 years old) at the initial assessment. Task persistence was widely distributed and higher among older…

Data from a longitudinal twin study of personality were analyzed for genetic influences utilizing scores from the Minnesota Multiphasic Personality Inventory and the California Psychological Inventory. (Author/JMB)