Mavioğlu Rezan Nehir, Boomsma Dorret I, Bartels Meike
Department of Molecular Biology and Genetics, Boğaziçi University, Istanbul, Turkey.
Department of Biological Psychology, Netherlands Twin Register, VU University Amsterdam, Van der Boechorststraat 1, 1081 BT, Amsterdam, The Netherlands.
Eur Child Adolesc Psychiatry. 2015 Nov;24(11):1381-8. doi: 10.1007/s00787-015-0680-x. Epub 2015 Feb 1.
The aim of this study was to investigate the degree to which genetic and environmental influences affect variation in adolescent optimism. Optimism (3 items and 6 items approach) and pessimism were assessed by the Life Orientation Test-Revised (LOT-R) in 5,187 adolescent twins and 999 of their non-twin siblings from the Netherlands Twin Register (NTR). Males reported significantly higher optimism scores than females, while females score higher on pessimism. Genetic structural equation modeling revealed that about one-third of the variance in optimism and pessimism was due to additive genetic effects, with the remaining variance being explained by non-shared environmental effects. A bivariate correlated factor model revealed two dimensions with a genetic correlation of -.57 (CI -.67, -.47), while the non-shared environmental correlation was estimated to be -.21 (CI -.25, -.16). Neither an effect of shared environment, non-additive genetic influences, nor quantitative sex differences was found for both dimensions. This result indicates that individual differences in adolescent optimism are mainly accounted for by non-shared environmental factors. These environmental factors do not contribute to the similarity of family members, but to differences between them. Familial resemblance in optimism and pessimism assessed in adolescents is fully accounted for by genetic overlap between family members.
本研究的目的是调查遗传和环境影响对青少年乐观主义差异的影响程度。通过修订后的生活取向测试（LOT-R）对来自荷兰双胞胎登记处（NTR）的5187名青少年双胞胎及其999名非双胞胎兄弟姐妹进行了乐观主义（3项和6项方法）和悲观主义评估。男性报告的乐观主义得分显著高于女性，而女性的悲观主义得分更高。遗传结构方程模型显示，乐观主义和悲观主义约三分之一的方差归因于加性遗传效应，其余方差由非共享环境效应解释。双变量相关因子模型揭示了两个维度，遗传相关性为-.57（可信区间-.67，-.47），而非共享环境相关性估计为-.21（可信区间-.25，-.16）。对于这两个维度，未发现共享环境、非加性遗传影响或定量性别差异的影响。这一结果表明，青少年乐观主义的个体差异主要由非共享环境因素造成。这些环境因素并非导致家庭成员的相似性，而是导致他们之间的差异。青少年中评估的乐观主义和悲观主义的家族相似性完全由家庭成员之间的遗传重叠所解释。
