Results from a genome-wide association study (GWAS) can be used to generate a polygenic score (PGS), an individual-level measure summarizing identified genetic influence on a trait dispersed across the genome. For complex, behavioral traits, the association between an individual's PGS and their phenotype may contain bias (from geographic,…

Anorexia nervosa is a complex behavioral disorder with the highest risk of death of any psychological disorder. Between 15% and 20% of those suffering from anorexia die from complications that are attributed either directly or indirectly to self-starvation. Heritability for anorexia is around 0.5, meaning about 50% of the risk for anorexia is…

Virtuous character development in children is correlated with parenting behavior, but the role of genetic influences in this association has not been examined. Using a longitudinal twin/sibling study (N = 720; Time 1 (T1) M[subscript age] = 12-14 years, Time 3 (T3) M[subscript age] = 25-27 years), the current report examines associations among…

The conflicts between nature and nurture are brought to the fore and challenges socio-scientific decision-making in science education. The multitude of meanings of these concepts and their roles in societal discourses can impede students' development of understanding for different perspectives, e.g. on gene technology. This study problematizes…

Purpose: Behavioral genetic studies of speech fluency have focused on participants who present with clinical stuttering. Knowledge about genetic influences on the development and regulation of normal speech fluency is limited. The primary aims of this study were to identify the heritability of stuttering and high nonfluency and to assess the…

Surveyed literature on genetics and fears and phobias to determine what might be heritable. Found, for ordinary fears among the general population, heredity appears to contribute mainly to a trait of general fearfulness and may be a major reason for the strong intercorrelation among different fears. Found evidence of little environmental…

Change in task persistence was assessed in two annual assessments using teachers', testers', and observers' ratings. Participants included 79 monozygotic and 116 same-sex dizygotic twin pairs who were in Kindergarten or 1st grade (4.3 to 7.9 years old) at the initial assessment. Task persistence was widely distributed and higher among older…

Describes biological influences on criminality. Illustrative data suggest a biological sex difference in criminality and heritable differences in this trait among individuals. Methods of isolating environmental influences are described. Author notes that using environment-friendly behavior genetic research designs is not only proper but would…

Examines the interplay between genes and environment and argues that the development of much individual variation can be explained in terms of relatively simple forms of underlying regulation. Looks at "sensitive periods," during which variation is produced by experience received at a particular age. Includes a discussion of the…

Twin children were videotaped hitting an inflated clown figure. Three behaviors (number of hits, intensity of hits, and number of quadrants hit) showed adequate response characteristics, rater reliability, and test-retest reliability. Twin analyses of the three behavioral ratings yielded no evidence of hereditary influence. (Author)

The home environment of nonadoptive and adoptive sibling pairs was assessed using the Home Observation for Measurement of the Environment when each sibling was one and two years of age. Correlations between home environment scores for nonadoptive siblings were greater than those for adoptive siblings. (BC)

Describes a methodology of behavior genetics in the context of twin and sibling/adoption design. This model was applied to cross-sectional data on cognitive development throughout the lifespan. Results from a twin and adoption study of general intelligence are presented to illustrate the use of the basic behavior genetic model in studying causes…

Correlations on subscales of Wechsler intelligence quotient tests and the Revised Beta Examination were obtained for biologically related and unrelated individuals in 181 adoptive families in the Texas Adoption Project. Generally higher correlations for biologically related individuals support the importance of genetic influence in intellectual…

Examined the effects of gender on academic achievement for 138 mono- and 125 dizygotic twin pairs, ranging in age from 6 to 12 years. Results suggested that individual differences in academic achievement may be more influenced by genetic than environmental variance in females, and by environmental than genetic variance in males. (BC)

This study examining children's understanding of biological inheritance addressed four central questions: (1) are young children able to distinguish between the relative influences of nature and nurture in their understanding of how physical characteristics versus behaviors and preferences develop in animals? (2) does children's understanding of…