Analysis of IQ's of 262 children and their 129 schizophrenic parents revealed no deleterious effects on the intellectual development of the children. (MH)

Behaviors of monozygotic and dizygotic twins that were indicative of wariness were observed when the twins were 14, 20, and 24 months of age. An index of inhibition constructed from observations showed internal consistency at all ages and stability across ages. Heritability was a factor at all ages. (BC)

Immediate and extended families of 66 stuttering children were investigated to determine frequencies of persistent and recovered stuttering. Recovery was far more common among females than males. Recovery or persistence was found to be transmitted, but the two types are not genetically independent, consistent with hypothesis that both forms share…

Observational measures of monozygotic and dizygotic twins' reactions to simulations of distress in others were obtained when the twins were 14 and 20 months old. Components of concern for others increased with age. Girls scored higher than boys on most measures. There was modest evidence for heritability of empathy. (BC)

A literature review of autism and tuberous sclerosis complex (TSC) substantiates a significant association between the two. Studies of 14 autistic probands and 13 TSC probands identified 7 TSC subjects with autism, who had more seizures and mental retardation than those without autism. More male TSC probands with autism than female were…

This study of 11 3-generation families supported the hypothesis of autosomal dominant inheritance with reduced penetrance. Data did not support an increased frequency of males, left-handedness, or autoimmune disorders in dyslexics. Severity was greater in males. Long-term outcome was comparable in dyslexics and nondyslexics. (JDD)

A study applied the polygenic threshold model to previously reported differences in gender ratios among children with reading disabilities and close family members with similar disabilities. The results were found to be predictable with the model. (MSE)

Analysis of pedigrees from parents of 69 preschool children who stuttered revealed that more male than female relatives ever stuttered but that female subjects who stuttered had more female relatives who ever stuttered than did male subjects. Segregation analyses suggest that transmission of a single major genetic locus increases the liability to…

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)

Sotos syndrome is characterized by high birth length, rapid bone growth, distinctive facial features, and possible verbal and motor delays. It is more common in males than females. Developmental deficits, specific learning problems, and speech/language delays may also occur. (DB)

A Study was conducted to test the hypothesis proposed by J. S. Symmes and J. L. Rapoport that a sex-linked recessive gene might account for the good spatial ability found among dyslexic readers, the familial pattern of the disorder, and the frequently reported sex ratio of three affected males to one female. Spatial/reasoning ability scores were…

Fragile X syndrome is an inherited genetic condition identified by a break or a weakness on the long arm of the X chromosome, and associated with mental retardation. Described on this single-sheet information guide are the prevalence of fragile X syndrome, its increased rate of incidence in boys as compared to girls, physical characteristics,…

Critiques an environmentalist view of the effects of nature and nurture on behavior. Argues for an interactionist position in which nature and nurture are totally and inextricably involved in each and every organismic response. (MP)

Critically reviews literature relevant to the hypothesis that a major X-linked gene determines spatial ability in man. It is concluded that belief in the validity of the hypothesis is unfounded. (Author/SS)