Masculinity and Femininity in Twin Children: Genetic and Environmental Factors

Abstract

Genetic and environmental origins of individual differences in masculine and feminine personality attributes were investigated in a sample of 38 monozygotic and 32 dizygotic twin pairs (total N = 140) during pre- and early adolescence. Self-report measures of both masculine and feminine characteristics were obtained for each child using 2 standardized instruments: the Children's Personality Attributes Questionnaire (CPAQ) and the Adolescent Self-Perception Inventory (ASPI). Multivariate biometrical analyses revealed significant genetic influences in all measures, accounting for 20%-48% of the observed variation in each. Environmental influences, which explained the remaining 52%-80% of variance in masculinity and femininity, were apparently specific to each individual and not shared by members of the same twin pair. The results underscore the importance of considering both genetic and environmental factors in gender-role development, particularly in studies of family resemblance.

Genetic and Environmental Influences on Individual Differences in Masculinity, Femininity, and Gender Diagnosticity: Analyzing Data From a Classic Twin Study

“…Several studies have estimated the heritability of M and F directly. For example, one small study of 38 monozygotic and 32 dizygotic twin pairs estimated the heritability of M and F measures in children and found, consistent with Loehlin's review, the following: (1) heritability was greater for M than for F, and (2) shared environmental effects were small (Mitchell, Baker, & Jacklin, 1989). However, this study was not able to estimate heritability separately for boys and girls because of its small sample size.…”

Gender Role Orientation and Anxiety Symptoms Among African American Adolescents

“…Biological explanations indicate that females are at a greater risk for anxiety due to sex-linked genetic and/or biological factors, such as hormonal changes and/or effects of androgens on the brain (see Earls, 1987;Hines, 2003;Mitchell, Baker, & Jacklin, 1989). In contrast, psychosocial explanations suggest that the gender disparity is a result of different socialization experiences for girls and boys (Block, 1983).…”

Children’s Perceptions of Sibling Conflict During Middle Childhood: Issues and Sibling (Dis)similarity

“…There is reason to believe that there are genetic contributions to individual differences in children's perceptions of sibling hostility. There is a growing literature showing that children's perceptions of selfcompetence and their perceptions of the quality of their relationships are heritable (Hur, McGue, & Iacono, 1998;Manke, McGuire, Reiss, Hetherington, & Plomin, 1995;McGuire, Neiderhiser, Reiss, Hetherington, & Plomin, 1994;McGuire, Manke, Saudino, Reiss, Hetherington, & Plomin, in press;Mitchell, Baker, & Jacklin, 1989). These self-perceptions may be mediated by other genetically influenced characteristics, such as temperament.…”