Fabsitz R R, Garrison R J, Feinleib M, Hjortland M
Behav Genet. 1978 Jan;8(1):15-25. doi: 10.1007/BF01067701.
In the NHLI Twin Study MZ twins are shown to "get together" substantially more often than DZ twins. With this result as an indicator of differences in shared environment, the assumption of equal shared environmental variation for MZ and DZ twins is assessed using nutritional data calculated from a food frequency questionnaire. Six nutrients show significant genetic variance for the total sample. However, when stratified on the basis of how frequently twins see each other, none of the nutrients shows significant genetic variance for both strata. A similar pattern is seen for several individual items from the questionnaire. In addition, four of the nutrients show significant correlation between the absolute difference in the nutrient intake of MZ twin pairs and how often they "get together." These data appear to show that unequal environmental effects may lead to falsely high estimates of genetic variance for nutrient intake.
在国家心肺血液研究所双胞胎研究中，同卵双胞胎“相聚”的频率明显高于异卵双胞胎。以这一结果作为共享环境差异的指标，利用通过食物频率问卷计算得出的营养数据，评估了同卵双胞胎和异卵双胞胎共享环境变异相等的假设。六种营养素在总样本中显示出显著的遗传变异。然而，当根据双胞胎见面的频率进行分层时，没有一种营养素在两个分层中都显示出显著的遗传变异。问卷中的几个单项也呈现出类似的模式。此外，四种营养素在同卵双胞胎对的营养素摄入量绝对差异与他们“相聚”的频率之间显示出显著相关性。这些数据似乎表明，不相等的环境效应可能导致对营养素摄入量遗传变异的高估。
