In white matter disorders such as leukodystrophies (LD), periventricular leucomalacia (PVL), or multiple sclerosis (MS), the hypomyelination or the remyelination failure by oligodendrocyte progenitor cells involves errors in the sequence of events that normally occur during development when progenitors proliferate, migrate through the white…

We describe an integrated theory of individual differences that traces the behavioral development of life history from genes to brain to reproductive strategy. We provide evidence that a single common factor, the K-Factor, underpins a variety of life-history parameters, including an assortment of sexual, reproductive, parental, familial, and…

Prereading and early reading skills of preschool twin children in Australia, Scandinavia and the United States were explored in a genetically sensitive design (max. N=627 preschool pairs and 422 kindergarten pairs). Analyses indicated a strong genetic influence on preschool phonological awareness, rapid naming and verbal memory. Print awareness,…

We report preliminary behaviour genetic analyses of reading and listening comprehension from The Colorado Learning Disabilities Research Center. Although the twin sample with these new measures is still of limited size, we find substantial, and significant, genetic influences on individual differences in both reading and listening comprehension.…

While praising the Sternberg et al. article, the present author has a couple of concerns. One is that the authors imply that the question of whether the Black-White IQ discrepancy has a genetic component should be a closed issue. I maintain that no argument should be intelligence evolved in colder climates because of the greater difficulty in…

Although a variety of studies have indicated that using statistical clustering techniques to examine genetic information may allow for geographically based groupings of individuals that tenuously map onto some conceptions of race, these studies have also indicated that the amount of genetic variation within these groupings is significantly larger…

Memories can have different strengths, largely dependent on the intensity of reinforcers encountered. The relationship between reinforcement and memory strength is evident in asymptotic memory curves, with the level of the asymptote related to the intensity of the reinforcer. Although this is likely a fundamental property of memory formation,…

Targeted mutagenesis in mice has shown that genes from a wide variety of gene families are involved in memory formation. The efficient identification of genes involved in learning and memory could be achieved by random mutagenesis combined with high-throughput phenotyping. Here, we provide the first report of a mutagenesis screen that has…

In the adult brain, the expression of NT-3 is largely confined to the hippocampal dentate gyrus (DG), an area exhibiting significant neurogenesis. Using a conditional mutant line in which the "NT-3" gene is deleted in the brain, we investigated the role of NT-3 in adult neurogenesis, hippocampal plasticity, and memory. Bromodeoxyuridine…

To test the hypothesis that the genetic etiology for reading disability may differ in males and females, data from identical and fraternal twin pairs were analysed using both concordance and multiple regression methods. The sample included 264 identical (129 male, 135 female) and 214 same-sex fraternal (121 male, 93 female) twin pairs in which at…

Using observational methods, we examined the social influences on laughing and smiling behavior in children with Angelman syndrome by systematically manipulating aspects of social interaction. Seven boys and 4 girls who were between 4 and 11 years of age and who had a confirmed maternal deletion of chromosome 15q11-q13 completed the study. Each…

The chance that someone will develop any disease is influenced by heredity and environment. Epilepsy is not an exception. Everybody inherits a unique degree of susceptibility to seizures. About 3 percent of the United States population is prone to seizures and will get epilepsy at some point of their lives (1). Two thirds of the people with…

Biological contributions to cognitive development continue to be conceived predominantly along deterministic lines, with proponents of different positions arguing about the preponderance of gene-based versus experience-based influences that organize brain circuits irreversibly during prenatal or early postnatal life, and evolutionary influences…

Williams syndrome (WS) is a rare genetic disorder resulting from a deletion on chromosome 7. A number of studies have shown that individuals with WS have a superior linguistic profile compared to their non-verbal abilities, however the evidence has been inconclusive, as many studies have disputed such a profile. The vast majority of studies on WS…

A history of the search for the structure of DNA, as revealed in the evolution of biochemistry and genetics textbooks, reveals that they are unacceptably tardy in presenting the current (or even the recent) state of knowledge. This problem places an extra burden on biology teachers to supplement these texts.