Analyzes composition reading performance data from identical and fraternal twin pairs in order to test the hypothesis that genetic influences are more important as a cause of reading disability in girls than in boys. Provides little or no evidence for the hypothesis of greater genetic influence on reading difficulties in girls than in boys. (SC)

The 22q11.2 microdeletion syndrome is a genetic disorder in children with many concomitant medical and developmental problems. Communication disorders are among the most common features of this syndrome and include articulation, language, resonance, and voice problems. Awareness of these features and a multidisciplinary approach are necessary for…

Data from a previous adoption study using the Wechsler Intelligence Scale for Children-Revised show that the genetic effect is reflected by psychometric "g" (general intelligence) to a greater degree than is the environmental effect. This finding is consistent with the hypothesis that "g" largely reflects the genetic component…

Comparison of the production of repetitive speech during conversations in 30 people with either fragile X syndrome, autistic disorder, or mental retardation not caused by fragile X found repetitive speech more prevalent among those with fragile X. Results support the hypothesis that such speech dysfluency reflects the effects of physiological…

Investigated genetic and environmental influences on the similarity and differences among five tests of cognitive abilities in 1,958 pairs of same-sex twins born in 1994 in the United Kingdom. Results suggest a developmental trend from modularity to molarity when considered in relation to multivariate genetic results later in life that show that…

Comments on Joseph's review of the genetics of attention deficit disorder, demonstrating errors of scientific logic and oversight of relevant research in Joseph's argument. Argues for the validity of twin studies in supporting a genetic link for ADHD and for the complementary role of nature and nurture in the etiology of the disorder. (JPB)

Answers the most important criticisms by Faraone and Biederman in their critique of Joseph's analysis of evidence supporting a genetic basis of attention deficit hyperactivity disorder. Argues that possible genetic and environmental influences in ADHD twin studies are confounded, obscuring inferences about genetic factors. (JPB)

Presents a series of elementary mathematical tools for re-representing pedigrees, pedigree generators, pedigree-driven database management systems, and case studies for exploring genetic relationships. (MKR)

Explores relationships among school students' (n=189) meaningful learning orientation, reasoning ability and acquisition of meaningful understandings of genetics topics, and ability to solve genetics problems. Results indicate that meaningful learning orientation best predicted students' understanding of genetics interrelationships while reasoning…

Recent research suggests that thinking of learning as an activity of the brain will lead to greater understanding of how and why students learn and how faculty can better facilitate learning. Discusses: genetic contributions; epigenetic growth; the synapse; stabilizing synapses; pedagogy; the role of emotions; kinds of learning; active learning;…

Presents an activity that uses chenille stems, colored yarn, plastic straws, and ingenuity to make a low-cost manipulative kit for modeling mitosis and meiosis. (ASK)

Describes a method for working with Coomassie Blue to analyze banding patterns of purified eukaryotic cell membrane proteins. (SAH)

Assessed the language development of 2,898 pairs of 2-year-old twins born in England and Wales using the MacArthur Communicative language Development Inventory, which assesses vocabulary and grammar. Moderate heritabilities were found for both. (Author/VWL)

Describes an interactive game designed to help students see and understand the dynamic relationship between DNA, RNA, and proteins. Appropriate for either a class or laboratory setting, following a lecture session about protein synthesis. (DDR)

Describes a card game that illustrates natural selection acting on random mutations with or without cumulative selection. (YDS)