The mother, father, and adolescent siblings from 675 families were observed interacting in problem-solving sessions. Siblings were monozygotic twins, dyzygotic twins, or full siblings in nondivorced families and full, half, and unrelated siblings in stepfamilies. Results suggested a greater genetic component to adolescent behavior than to parent…

Pedigree analysis of 12 young adults (9 of whom had learning disabilities) indicated that learning disability (LD) was strongly familial but that the type of disability (reading or math) was not directly inherited. Autoimmune disorders were significantly correlated with LD. In seven of the LD families, adults failed to overcome earlier reading and…

Suggests that experiential canalization is appropriately applied to constraints caused by the behavior of an organism or members of its species. When other aspects of the environment propel the organism to develop in certain ways, this process reflects adaptation to the environment. Conditions for evolution of experience as a guide to development…

This study provides support for a potential subclinical marker in the executive function domain of siblings (n=18, ages 8-18) of autistic individuals, compared to learning-disabled controls. No group differences in theory-of-mind abilities were found. The need to develop more sensitive measures is discussed. (Author/JDD)

An exercise that uses a common bacterium, E. coli, in great numbers, to detect a demonstrable change in the ability of some cells to become resistant to the common antibiotic streptomycin is presented. The procedure for preparing and pouring the gradient antibiotic plates is provided. The advantages of using the Basic Fuchsin in the agar are…

Parents of 21 well-functioning autistic children were examined. Clinical details of the eight parents diagnosed as schizoid are analyzed, leading to the conclusion that one etiological factor may be a genetic predisposition to schizoid personality traits. Global and specific developmental delays in the autistic children's siblings were not found.…

The prevalence of epilepsy was correlated with the severity and type of encephalopathy of 1,023 individuals with mental retardation. A total of 326 individuals were diagnosed with epilepsy. Results indicated a low percentage of epilepsy in chromosomic-genetic and young adult encephalopathies and a high prevalence when the neurodeficit was…

A total of 127 pairs of twins completed a measure of personality at 20 and 30 years of age. Analyses revealed that variance in negative emotionality was the result of diminishing genetic influence; personality stability was the result of genetic factors; and personality change was the result of environmental factors. (BC)

Assessed the family environment and personality of 400 pairs of 59-year-old twins. Genetic influences on extraversion and neuroticism were related to genetic influences on the family environment factors of relationship and personal growth but not to the factor of system maintenance. (BC)

Mothers attributed their children's outcomes to either child-rearing practices, genetics, or environment. It was predicted that mothers of only children and gifted children would attribute more importance to child rearing than would mothers of multiple children and special education children. Predictions were supported across academic, social, and…

Rapid-cycling brassicas can be used in the classroom to teach concepts such as plant growth, tropisms, floral reproduction, pollination, embryonic development, and plant genetics. Directions on how to obtain them for classroom use and how they may be grown are included. Practical physiology and genetics exercises are listed. (KR)

Applies inverse Bayesian analyses to data from three large family studies of reading disability to estimate posterior probability that an offspring will be affected. Finds that offspring risk rates were significantly elevated if a parent reported a history of reading disability. Suggests the use of family history as a component in clinical…

Investigates genetic influences on reading in a sample of 285, 13-year-old twins. Finds the heritability of disability for reading recognition to be nonsignificant but that spelling had a substantial genetic contribution to all levels of disability. Suggests two possible independent aspects of phonological ability, each influenced by genetic…

Applies an extension of an earlier multiple regression model for twin analysis to the problem of detecting linkage in a quantitative trait. Detects a number of possible linkages, indicating that the approach is effective. Discusses detecting genotype-environment interaction and the issue of power. (RS)

Dramatic developments in brain research and imaging technology are rapidly advancing our understanding of the human brain. The new biologically based brain theories suggest that "nature" dominates "nurture" and that many current beliefs about instruction, learning, and memory are wrong. This article explains neural Darwinism…