Describes a methodology of behavior genetics in the context of twin and sibling/adoption design. This model was applied to cross-sectional data on cognitive development throughout the lifespan. Results from a twin and adoption study of general intelligence are presented to illustrate the use of the basic behavior genetic model in studying causes…

Social scientists are often concerned that research on biological causes of behavior will encourage biologically-based public policy. By simultaneously examining both social and biological causes of behavior, biosocial research models prevent simplistic biological thinking. Concludes that biosocial models clarify ethical problems rather than…

This article reviews and critiques the research on possible genetic factors in stuttering. The failure to consider epidemiologic factors is thought to have biased previous research, but recent data provide evidence that spontaneous recovery and chronicity are influenced by genetic factors. Findings support previous conclusions about combined…

In contrast to the hypothesis that dyslexics possess phonological deficits of neurological origin, the paper proposes that the source of the deficit is primarily experiential. Evidence from normal reading and spelling development as well as from comparisons of dyslexic and nondyslexic readers is offered. (Author/DB)

In response to Coles (EC 220 146), the article examines evidence of the roles of intrinsic biological characteristics and the environment in learning disability and suggests that learning disability is a biological susceptibility manifested in an environment promoting its expression. (DB)

Data from 148 identical and 111 fraternal twin pairs in which at least 1 member had a reading disability were statistically analyzed. Results suggest that genetic and shared-environment influences both contribute to the observed covariance between reading and mathematical deficits. (Author/DB)

Correlations on subscales of Wechsler intelligence quotient tests and the Revised Beta Examination were obtained for biologically related and unrelated individuals in 181 adoptive families in the Texas Adoption Project. Generally higher correlations for biologically related individuals support the importance of genetic influence in intellectual…

The entire thesis of "The Bell Curve" disintegrates due to biased use of data, misrepresentations, and logical inconsistencies. Five basic flaws are: inferring causality from correlation, use of dubious racial categories, contradictory arguments concerning the immutability of cognitive ability and the relative contributions of heredity…

A research study of identical twins, by Thomas J. Bouchard Jr., discloses that genetics exert a stronger influence over personality than we thought. Parents and teachers are advised to be active and alert observers of children's interests and talents to provide appropriate tools and resources to develop these propensities. (MLF)

Whether genetic and environmental effects on academic achievement changed as a function of the quality of children's environment was studied with 1664 pairs of full siblings, 366 pairs of half siblings, and 752 pairs of cousins. Little evidence was found of genotype-environment interactions. (SLD)

Describes the "American Renaissance" Conference of 1998 at which 200 scholars from the extreme right gathered to discuss theories of racial differences. Focuses on some of the racial extremists, including one lecturer espousing fertility controls on nonwhites. (SLD)

Investigated the etiology of several measures of cognitive delay in over 3,000 pairs of 2-year-old twins, focusing on group-differences heritability for general and specific cognitive delays. Concluded that because the genetic and environmental origins of verbal and performance delays in infancy differ, they are better considered separately rather…

Examined the effects of gender on academic achievement for 138 mono- and 125 dizygotic twin pairs, ranging in age from 6 to 12 years. Results suggested that individual differences in academic achievement may be more influenced by genetic than environmental variance in females, and by environmental than genetic variance in males. (BC)

Virtual twins are unrelated siblings of the same age who are reared together from early infancy (UST-SA). Study uses a sample of 90 UST-SA pairs to comparatively assess the similarity of IQ subtest profile correlations for UST-SAs and twin pairs. Findings support explanatory models of intelligence that include genetic factors, demonstrating that…

Describes evolutionary developmental psychology as the study of the genetic and ecological mechanisms that govern the development of social and cognitive competencies common to all human beings and the epigenetic (gene-environment interactions) processes that adapt these competencies to local conditions. Outlines basic assumptions and domains of…