Black women with a family history of breast cancer are much less likely than Whites to get genetic counseling, in part because of the mistaken notion that the genetic form of the illness is a White woman's disease, researchers say. While breast cancer generally is more common among White women, some data suggest both races have similar rates of…

The contentious nature-nurture debate in developmental psychology is poised to reach a rapprochement with contemporary concepts of gene-environment interaction, transaction, and fit. Discoveries over the past decade have revealed how neither genes nor the environment offers a sufficient window into human development. Rather, the most important…

Environmental and genetic explanations have been given for Black-White racial differences in intelligence and other traits. In science, viable, alternative hypotheses are ideally given equal Bayesian prior weights; but this has not been true in the study of racial differences. This article advocates testing environmental and genetic hypotheses of…

Because there are so many chance factors that potentially affect the psychological development of gifted students, the outhor has sorted them into categories. For example, there are genetic, lifestyle, environmental, overarching vs. instance, experiential, and coincidental chance factors. To do justice to this topic, a series of columns will focus…

The genetic and environmental etiologies of sex-typed behavior were examined during the preschool years in a sample of 3,990 three- to four-year-old twin and nontwin sibling pairs. Results showed moderate genetic and significant shared environmental influence for boys and substantial genetic and moderate shared environmental influence for girls.…

Although it is well established that school characteristics (SCH) and socio-economic status (SES) are associated with academic achievement (ACH), these correlations are not necessarily causal. Because academic achievement shows substantial genetic influence, it is useful to embed such investigations in genetically sensitive designs in order to…

This speech by a researcher into the genetic bases of dyslexia, attention deficit hyperactivity disorder (ADHD), and their etiological overlap, first honors four pioneers in the field (Samuel Orton, Bertil Hallgren, Isabelle Liberman, and Norman Geschwind); then updates knowledge about the genetics of dyslexia and comorbidity with ADHD and certain…

The authors developed a project with funding from Science Year in conjunction with a number of Belfast primary schools in which they introduced the process of DNA fingerprinting as part of a wider programme to investigate children's attitudes to science. There are two main difficulties in taking DNA fingerprinting into the primary school in any…

Background: The delayed oculomotor response (DOR) task requires response inhibition followed by movement of gaze towards a known spatial location without a current stimulus. Abnormalities in response inhibition and in the spatial accuracy of the eye movement are found in individuals with schizophrenia and in many of their relatives, supporting the…

Background: There is a growing interest in the study of the genetic origins of comorbidity, a direct consequence of the recent findings of genetic loci that are seemingly linked to more than one disorder. There are several potential causes for these shared regions of linkage, but one possibility is that these loci may harbor genes with manifold…

Background: Williams syndrome (WS), a neurodevelopmental disorder, is characterized by pervasive cognitive deficits alongside a relative sparing of auditory perception and cognition. A frequent characteristic of the phenotype is adverse reactions to, and/or fascination with, certain sounds. Previously published reports indicate that people with WS…

Background: We investigated the aetiology of language impairment in 579 four-year-old twins with low language performance and their co-twins, members of 160 MZ twin pairs, 131 same-sex DZ pairs and 102 opposite-sex DZ pairs. Methods: Language impairment in 4-year-olds was defined by scores below the 15th percentile on a general factor derived from…

Background: Brain morphology and physiological measures in schizophrenia have yielded inconsistent results. This may be due in part to difficulties in ascertaining precisely to what degree each measure deviates from its genetically and environmentally determined potential level. We attempted to surmount this problem in a paradigm involving…

Several different methodological approaches that have been used in studying language in children with autism are outlined. In classic studies, children with autism are compared to comparison groups typically matched on age, IQ, or mental age in order to identify which aspects of language are uniquely impaired in autism. Several methodological…

Previous studies have suggested that among affected sib pairs with autism there is an increase in the frequency of twins over what would be expected in comparison to the prevalence of twins in the general population. In this study we sought to determine whether "sub-threshold" autistic traits were more pronounced in twins than in non-twins. The…