title: Common genetic effects of gender atypical behavior in childhood and sexual orientation in adulthood: a study of Finnish twins.
abstract: The existence of genetic effects on gender atypical behavior in childhood and sexual orientation in adulthood and the overlap between these effects were studied in a population-based sample of 3,261 Finnish twins aged 33-43 years. The participants completed items on recalled childhood behavior and on same-sex sexual interest and behavior, which were combined into a childhood gender atypical behavior and a sexual orientation variable, respectively. The phenotypic association between the two variables was stronger for men than for women. Quantitative genetic analyses showed that variation in both childhood gender atypical behavior and adult sexual orientation was partly due to genetics, with the rest being explained by nonshared environmental effects. Bivariate analyses suggested that substantial common genetic and modest common nonshared environmental correlations underlie the co-occurrence of the two variables. The results were discussed in light of previous research and possible implications for theories of gender role development and sexual orientation.
authors.affiliation: Center of Excellence for Behavior Genetics, Department of Psychology, Abo Akademi University, 20500, Turku, Finland. katarina.alanko@abo.fi
authors.forename: Katarina
authors.initials: K
authors.lastname: Alanko
authors.forename: Pekka
authors.initials: P
authors.lastname: Santtila
authors.forename: Nicole
authors.initials: N
authors.lastname: Harlaar
authors.forename: Katarina
authors.initials: K
authors.lastname: Witting
authors.forename: Markus
authors.initials: M
authors.lastname: Varjonen
authors.forename: Patrik
authors.initials: P
authors.lastname: Jern
authors.forename: Ada
authors.initials: A
authors.lastname: Johansson
authors.forename: Bettina
authors.initials: B
authors.lastname: von der Pahlen
authors.forename: N Kenneth
authors.initials: NK
authors.lastname: Sandnabba
mesh_terms: D000328:Adult; D001519:Behavior; D002648:Child; D004777:Environment; D005163:Factor Analysis, Statistical; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D010641:Phenotype; D012727:Sex Characteristics; D019529:Sexuality; D011795:Surveys and Questionnaires; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic