Flom Megan, Wang Manjie, Uccello Kendra J, Saudino Kimberly J
Department of Psychological & Brain Sciences, Boston University, 64 Cummington Mall, Room 100, Boston, MA, 02215, USA.
Behav Genet. 2018 Nov;48(6):432-439. doi: 10.1007/s10519-018-9924-0. Epub 2018 Sep 26.
The sources of individual differences in both observed and parent-rated positive affect (PA) were examined in a sample of 304 3-year-old twin pairs (140 MZ, 164 DZ). Based on model-fitting analyses, individual differences in observed PA were attributed to moderate genetic and high nonshared environmental factors, but not shared environmental factors. In contrast, shared environmental effects accounted for over half of the variance in parent-rated PA and genetic and nonshared environmental effects were more modest. The genetic correlation across the two measures was high, indicating substantial overlap between genetic factors influencing the two. It was these overlapping genetic effects that fully explained the phenotypic correlation between both measures. There was no significant covariance between the environmental influences on parent rated and observed PA. Thus, the two measures of PA in early childhood have common genetic underpinnings, whereas environmental influences are measure-specific. Measurement implications are discussed.
在一个由304对3岁双胞胎（140对同卵双胞胎，164对异卵双胞胎）组成的样本中，研究了观察到的和父母评定的积极情绪（PA）方面个体差异的来源。基于模型拟合分析，观察到的PA个体差异归因于中等程度的遗传因素和高度的非共享环境因素，而非共享环境因素。相比之下，共享环境效应占父母评定PA方差的一半以上，而遗传和非共享环境效应则较为适度。两种测量方法之间的遗传相关性很高，表明影响两者的遗传因素存在大量重叠。正是这些重叠的遗传效应充分解释了两种测量方法之间的表型相关性。父母评定的PA和观察到的PA在环境影响方面没有显著的协方差。因此，幼儿期PA的两种测量方法有共同的遗传基础，而环境影响是特定于测量方法的。文中讨论了测量的意义。
