Studied genetic and environmental origins of individual differences in adults' (N=386) ratings of their current family environment using Moos Family Environment Scales (FES). Found 25 percent of adults' FES scores due to genetic differences. Found environment in which they were reared had little effect on adults' ratings of their family…

Objective: Familial risk for depression results from both biological and social influences. These may also be associated with other characteristics, including alcohol use, smoking, and body mass index (BMI), and with environmental risks such as social problems, life events, and educational level, all of which may be associated with depression in…

Although it is well established that school characteristics (SCH) and socio-economic status (SES) are associated with academic achievement (ACH), these correlations are not necessarily causal. Because academic achievement shows substantial genetic influence, it is useful to embed such investigations in genetically sensitive designs in order to…

Conducted a trivariate genetic analysis of the Home Observation for Measurement of the Environment (HOME), Mental Development Index (MDI), and Task Orientation (TO). Found that for 101 nonadoptive and 92 adoptive sibling pairs at 12 and 24 months of age, TO explained the remaining genetic variance on the HOME not explained by the MDI. (MDM)

Using a longitudinal, large-scale sample of British twins, we addressed the prediction of both cognitive abilities and behavioral adjustment from eight domains of environmental risk: minority status, socio-economic status, maternal medical factors, twin medical factors, maternal depression, chaos within the home environment, and parental feelings…

Discusses the concept of temperament interactions in the context of statistical interaction. Categorizes temperament interactions that involve temperament as an independent variable, as a dependent variable, or as both. Describes use of hierarchical multiple regression for the analysis of temperament interactions. (Author/CI)

Etiology of verbal and performance delays were investigated in a large population sample of twins at 2 and 3 years (N=2,449 pair). Longitudinal genetic analyses indicated substantial heritability of verbal delay from 2 to 3 years, especially in combination with performance delay. Results suggest a strong genetic contribution to verbal delay…

This chapter argues for the value of sibling research in addressing behavioral genetic issues on the etiology of individual differences. The goal of the report is to provide a set of simple and practical examples of sibling analyses in order to highlight the importance of incorporating siblings in future research. It begins with a discussion of…

This study of 707 sibling pairs, 10- to 18-years-old, examined parent-child and sibling interactions to determine the effects of genetics on family environment. The sample included identical and fraternal twins and full siblings in nondivorced families, as well as full, half, and unrelated siblings in divorced families. Found significant genetic…

The current study examined whether socioeconomic status (SES) and chaos in the home mediate the shared environmental variance associated with cognitive functioning simultaneously estimating genetic influences in a twin design. Verbal and nonverbal cognitive development were assessed at 3 and 4 years for identical and same-sex fraternal twin pairs…

This behavioral genetic study examined perceived competence and self-worth in same-sex twins, siblings, and stepsiblings 10 to 18 years old, and again 3 years later. Findings at second assessment showed six of seven subscales heritable. Genetic contributions to stability were found for perceived scholastic competence, athletic competence, physical…

Parent/infant relationships were investigated among 50 biologically related families selected to provide a control group for an adoption study of rate differences in communicative development in infancy. In addition, a path analysis of genetic and environmental influences on communicative development is presented incorporating the overall sample.…

Used the Sibling Inventory of Differential Experience with 396 adolescent and young adult children to determine the extent to which genetic differences between siblings or sibling differences in family constellation variables were responsible for differential experiences. (HOD)

This longitudinal monozygotic (MZ) twin differences study explored associations between birthweight and early family environment and teacher-rated behaviour problems and academic achievement at age 7. MZ differences in anxiety, hyperactivity, conduct problems, peer problems and academic achievement correlated significantly with MZ differences in…

Examined nonshared environmental (NSE) influences on twin preschoolers' behavior independent of genetics. Found that within-pair parenting differences correlated with monozygotic differences in behavior. For the extreme 10 percent of the parenting-discordant and behavior-discordant distributions, average NSE effect size was 11 percent, suggesting…