Learn More
The structure of temperament proposed by the New York Longitudinal Study (NYLS) of Thomas and collaborators (1963, 1968) was compared to Buss and Plomin's (1975) EASI temperament theory. An objective inventory was developed for the NYLS temperaments. Mothers rated 182 children on both NYLS and EASI temperaments. Only two of the nine NYLS dimensions,(More)
Attention-deficit hyperactivity disorder (ADHD) affects approximately 3%-5% of children in the United States. In the current psychiatric nomenclature, ADHD comprises three subtypes: inattentive, hyperactive-impulsive, and combined. In this study, we used four analytic strategies to examine the association and linkage of the dopamine transporter gene (DAT1)(More)
This article examines how parental education level moderates the genetic and environmental contributions to variation in verbal IQ. Data are from 1909 non-Hispanic Whites and African American sibling pairs from the National Longitudinal Study of Adolescent Health, which obtained nationally-based samples of identical (MZ) twins, fraternal (DZ) twins, full(More)
This study investigated (a) genetic and environmental contributions to the relationship between family and school environment and depressed mood and (b) potential sex differences in genetic and environmental contributions to both variation in and covariation between family connectedness, school connectedness, and adolescent depressed mood. Data are from(More)
Parents of young children completed questionnaires that assessed attitudes toward parenting and specific parenting practices, the emotional atmosphere of the home, and parental personality. These parents were themselves either identical twins (n = 90), fraternal twins (n = 56), or adoptive siblings (n = 40). Model-fitting results implicate modest genetic(More)
A polymorphism in the dopamine receptor 4 gene (DRD4) has been related to novelty seeking, Tourette's syndrome, and attention deficit hyperactivity disorder (ADHD). The variability is in a 48-bp repeat in exon 3 of the gene (a transmembrane region). This study examined the relation of the 7-repeat (i.e., high-risk) allele to questionnaire-based diagnoses of(More)
The transmission disequilibrium test (TDT), designed as a test of linkage in the presence of association (i.e. linkage disequilibrium), has received considerable attention in the recent statistical genetics literature due to its advantages over other within-family analytic methods. One limitation of the conventional TDT is its application solely to linkage(More)
Variations in ratings of externalizing and internalizing symptoms may contain a trait (i.e., shared view) component when behavioral symptoms that generalize across context are perceived and an individual view component when they are misperceived of when each informant has access to different symptoms. Using a LISREL model, we estimated that the trait and(More)