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…

Genetic research has shown that dyslexia is familial, substantially heritable, and heterogeneous in its genetic mechanisms. Evidence also supports the view that the primary symptom in dyslexia is a deficit in the phonological coding of written language, a symptom that appears to be heritable. (Author/JDD)

Explores the role of biological causation in the development of behavioral outcomes. Genes and other biological structures constitute complex behavior, but the behavior of complex organisms cannot be derived from the biogenetic units of which it is composed. (SLD)

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…

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…

The application of component analysis to phenotypic, genetic, and environmental correlation matrices is discussed. Formulas for computation of component scores and the interpretation of factors is discussed. An example is presented. (Author/JKS)

A review of current literature suggests that many cases of autism may well have both environmental and genetic etiologies and that more than one genetic locus is likely. Some evidence suggests that some genetic abnormality of language or sociability is inherited which then interacts with other factors to produce autism. (DB)

Focuses upon self-preservation, as it pervades the general patterns of behavior of all organisms, over the totality of biological evolution. Asserts that self-preservation has definable limitations that can be modeled mathematically. Suggests natural selection does not invariably favor tendencies toward self-preservation. Argues that reproduction…

Studied 715 twins and singletons to document heritable influences on temperament during toddler and preschool ages. Found substantial shared environmental influence on positive affect and additive genetic influence on emotion regulation. Intraclass correlations from many scales showed no evidence of "too-low" dizygotic correlations that…

This article presents replies to published comments on the authors' original article (R. L. Sternberg, E. L. Grigorenko, and K. K. Kidd. G. Carey cited in his response to their article a study by Tang et al. (2005) showing that "of 3,636 subjects of varying race/ethnicity, only 5 (0.14%) showed genetic cluster membership different from their…

Studies by the late English psychologist Cyril Burt of IQ scores of separated twins strongly suggested that intelligence was inherited. A summary of recent research costs doubt upon the validity of Burt's work. (SL)

In "The Mismeasure of Man," a history of efforts to measure intelligence, Stephen Jay Gould is highly selective in his account, and tests for scientific truth by the standards of his own social and political convictions. Specifically, to combat racist approaches to theories of intelligence, Gould presses for equal and opposite bias.…

A series of environmental-genetical analyses of the left-handedness of 1,950 college students indicates that left-handedness is familial: it is more frequent in families in which at least one parent is left-handed. (Author/CM)

Describes biological influences on criminality. Illustrative data suggest a biological sex difference in criminality and heritable differences in this trait among individuals. Methods of isolating environmental influences are described. Author notes that using environment-friendly behavior genetic research designs is not only proper but would…