Sexual orientation in a US national sample of twin and nontwin sibling pairs
Sexual orientation in a US national sample of twin and nontwin sibling pairs
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DOI：
10.1176/appi.ajp.157.11.1843
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发表时间：
2000-11-01
影响因子：
17.7
通讯作者：
Kessler, RC
中科院分区：
文献类型：
--
作者：
Kendler, KS;Thornton, LM;Kessler, RC
目的：虽然先前的研究表明性取向受熟悉的因素影响，可能部分是遗传的，但这些研究依赖于不具代表性和潜在偏见的样本。作者试图在更具代表性的样本中估计遗传和环境因素在决定性取向中的作用。方法：在美国全国双胞胎和非双胞胎兄弟姐妹样本中，通过自我报告问卷上的单个项目评估性取向。性取向分为异性恋或非异性恋(双性恋或同性恋)。作者将同卵双胞胎的性取向相似性与同性别异卵双胞胎、所有异卵双胞胎、同性别异卵双胞胎和兄弟姐妹、以及所有异卵双胞胎和兄弟姐妹的相似性进行了比较。结果：所有的分析都显示出性取向的家族相似性。同卵双胞胎的相似性大于异卵双胞胎或异卵双胞胎加非双胞胎兄弟姐妹。生物测定双胞胎模型表明，性取向在很大程度上受到遗传因素的影响，但家庭环境也可能起到作用。没有发现违反同卵双胞胎和异卵双胞胎的平等环境假设的证据。结论：至少部分是遗传的家庭因素影响性取向。这些分析的结果应该在统计能力低的背景下解释，并使用单一项目来评估性取向的复杂表型。
Objective: Although previous studies have suggested that sexual orientation is influenced by familiar factors, which may be partly genetic, these studies have relied on unrepresentative and potentially biased samples. The authors attempted to estimate the role of genetic and environmental factors in the determination of sexual orientation in a more representative sample.Method: Sexual orientation was assessed by a single item on a self-report questionnaire in a U.S. national sample of twin and nontwin sibling pairs. Sexual orientation was classified as heterosexual or nonheterosexual (bisexual or homosexual). The authors compared the similarity of sexual orientation in the monozygotic twins to the similarity in the same-sex dizygotic twins, all dizygotic twins, the same-sex dizygotic twins and sibling pairs, and all dizygotic twins and sibling pairs. Biometrical twin analyses were performed.Results: All analyses demonstrated familial resemblance for sexual orientation. Resemblance was greater in the monozygotic twins than in the dizygotic twins or in the dizygotic twins plus nontwin siblings. Biometrical twin modeling suggested that sexual orientation was substantially influenced by genetic factors, but family environment may also play a role. No evidence was found for a violation of the equal-environment assumption regarding monozygotic and dizygotic twin pairs.Conclusions: Familial factors, which are at least partly genetic, influence sexual orientation. The results of these analyses should be interpreted in the context of low statistical power and the use of a single item to assess the complex phenotype of sexual orientation.