The prevalence of child abuse in 48 families of twins as compared to 24 families of singleton infants was studied. Journal Availability: See EC 152 486. (Author/SEW)

Deconstructs mainstream twin studies to show the relationship between twins research and race, gender, and class issues related to intelligence and IQ measures. The paper notes that genetic determinism drawn from twin studies based on the assumption that genetics predominates the environment in the transmission of human intelligence is…

Data from 236 pairs of black twins and white twins aged 13-17 years were used to examine genetic and environmental factors influencing cranial size, an indirect estimate of brain volume. Genetic factors are required to account for the phenotypic variance in cranial capacity. (SLD)

Studies of families, twins, and adoptees support a genetic predisposition to alcoholism. Alcohol metabolism may affect the regulation of alcohol intake, because interference with production or elimination of the alcohol metabolite acetaldehyde has behavioral effects. Ongoing research is examining individual and tribal differences in alcohol…

Analyzes skills involved in children's (twins and singletons) performance on communicative referential tasks and developmental changes in type and quality of messages. Finds no differences in number and type of information elements, but different interactive styles and strategies between twins and singletons, with twins showing a partner-dependent…

Fifty-seven same-sex twin sets (32 monozygotic and 25 dizygotic) were examined for concordance of speech and language disorders. Monozygotic twins had a higher concordance than dizygotic twins and also were more similar in the types of disorders they presented than dizygotic twins. Positive family histories were reported for both groups.…

The structural and external validity of the Tridimensional Personality Questionnaire (TPQ) and the relations among TPQ lower-order and higher-order scales and those of the Multidimensional Personality Questionnaire were examined. Results for 1,236 adults support the TPQ's validity but indicate its failure to operationalize portions of the…

Findings indicated that zygosity was not related to behavioral scores during the neonatal period, and that environment substantially influenced neonatal temperament. Specific perinatal indicators of risk were found to account for some of the intrapair differences in behavioral variables. (RH)

Retrospective parental reports of earlier "twin language" were obtained for 82 twin pairs (ages 7 to 13), in which at least one twin had a speech-language impairment, and 94 control twin pairs. Parental report of twin language was higher for children with speech-language impairments than for those with normal language. (Author/CR)

Using a new twins sample, presents new estimates of schooling returns and "ability" bias and tests that bias's significance. Ability bias may exist even if ability's genetically-endowed component does not affect schooling decisions directly when correlated with other family characteristics (like income) that do affect schooling. (19…

Examined the relationship between elementary cognitive tasks and the general factor of intelligence ("g") through tests administered to 568 elementary school students in a study of twins. Findings indicate a memory processing component in addition to a general information processing component contributing to "g" estimates. (SLD)

Background: Twin research has consistently shown substantial genetic influence on individual differences in cognitive ability; however, much less is known about the genetic and environmental aetiologies of school achievement. Aims: Our goal is to test the hypotheses that teacher-assessed achievement in the early school years shows substantial…

Objective: To examine the etiologies of covariation of childhood sleep problems and other behavioral/emotional problems in young children. Method: The parents of more than 6,000 twin pairs provided information on their twins' anxiety, conduct, and hyperactivity at ages 3, 4, and 7 by completing the Strengths and Difficulties Questionnaire.…

Prosocial behavior is important for the functioning of society. This study investigates the extent to which environment shared by family members, nonshared environment, and genetics account for children's prosocial behavior. The prosocial behavior of twins (9,424 pairs) was rated by their parents at the ages of 2, 3, 4, and 7 and by their teachers…

Background: Parenting factors may be important to the development of attributional style in adolescence, which in turn relates to depression symptoms. These relationships have mainly been considered in terms of social risk mechanisms, and little is known about the role of genetic influences. Method: Self-reported measures of attributional style,…