Minnesota Center for Twin and Family Research, Department of Psychology, University of Minnesota, Elliott Hall, 75 E River Pkwy, Minneapolis, MN, 55455, USA,
Behav Genet. 2013 Nov;43(6):491-504. doi: 10.1007/s10519-013-9616-8. Epub 2013 Sep 25.
In the past, shared environmental influences on personality traits have been found to be negligible in behavior genetic studies (e.g., Bouchard and McGue, J Neurobiol 54:4-45, 2003). However, most studies have been based on biometrical modeling of twins only. Failure to meet key assumptions of the classical twin design could lead to biased estimates of shared environmental effects. Alternative approaches to the etiology of personality are needed. In the current study we estimated the impact of shared environmental factors on adolescent personality by simultaneously modeling both twin and adoption data. We found evidence for significant shared environmental influences on Multidimensional Personality Questionnaire Absorption (15% variance explained), Alienation (10%), Harm Avoidance (14%), and Traditionalism (26%) scales. Additionally, we found that in most cases biometrical models constraining parameter estimates to be equal across study type (twins vs. adoptees) fit no worse than models allowing these parameters to vary; this suggests that results converge across study design despite the potential (sometimes opposite) biases of twin and adoption studies. Thus, we can be more confident that our findings represent the true contribution of shared environmental variance to personality development.
过去，行为遗传学研究发现，人格特质的共同环境影响可以忽略不计（例如，Bouchard 和 McGue，J Neurobiol 54:4-45, 2003）。然而，大多数研究仅基于双胞胎的生物计量建模。未能满足经典双胞胎设计的关键假设可能会导致共同环境效应的估计偏差。需要替代人格病因的方法。在当前的研究中，我们通过同时对双胞胎和收养数据进行建模，估计了共同环境因素对青少年人格的影响。我们发现，多维度人格问卷吸收（15%的方差解释）、疏远（10%）、回避风险（14%）和传统主义（26%）量表存在显著的共同环境影响。此外，我们发现，在大多数情况下，将参数估计限制在研究类型（双胞胎与被收养者）相同的生物计量模型拟合得并不比允许这些参数变化的模型差；这表明，尽管双胞胎和收养研究存在潜在的（有时是相反的）偏差，但研究设计的结果是收敛的。因此，我们可以更加确信，我们的发现代表了共同环境方差对人格发展的真正贡献。
