Saudino Kimberly J, Zapfe Jeffrey A
Psychology Department, Boston University, 64 Cummington Street, Boston, MA 02215, USA.
Child Dev. 2008 Jul-Aug;79(4):930-43. doi: 10.1111/j.1467-8624.2008.01168.x.
Although genetic influences on individual differences in activity level (AL) are well documented, few studies have considered the etiology of AL from a contextual perspective. In the present study, cross-situational and context-specific genetic effects on individual differences in AL at age 2 were examined. The AL of 312 twin pairs (144 monozygotic and 168 dzygotic) was mechanically assessed with actigraphs in the home and in laboratory test and play situations. AL displayed significant genetic variance in all 3 situations. Moreover, actigraph scores significantly correlated across situations. Multivariate genetic model-fitting analyses found that the observed cross-situational continuity in AL was due entirely to genetic factors. Situational differences in AL arise from genetic, shared environmental, and nonshared environmental influences.
尽管基因对活动水平（AL）个体差异的影响已有充分记录，但很少有研究从情境角度考虑AL的病因。在本研究中，考察了2岁时跨情境和特定情境的基因效应与AL个体差异的关系。使用活动记录仪在家中、实验室测试和玩耍情境下，对312对双胞胎（144对同卵双胞胎和168对异卵双胞胎）的AL进行了机械评估。在所有三种情境中，AL均表现出显著的遗传变异。此外，活动记录仪得分在不同情境间显著相关。多变量遗传模型拟合分析发现，观察到的AL跨情境连续性完全归因于基因因素。AL的情境差异源于基因、共享环境和非共享环境的影响。
