Guo Guang
Carolina Population Center and Department of Sociology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3210, USA.
Twin Res Hum Genet. 2006 Feb;9(1):113-21. doi: 10.1375/183242706776402920.
Two observations suggest a genetic similarity among close friends: (1) the observed similarity among friends in certain traits and behaviors; (2) the evidence that many of these traits and behaviors have a genetic component. This hypothesis is tested using monozygotic (MZ) twins, dizygotic (DZ) twins, full biological siblings, and their best friends from the National Longitudinal Study of Adolescent Health (Add Health). Whether the resemblance between MZ twins' friends is larger than that between friends of DZ twins and full siblings is investigated with respect to 4 individual traits or behaviors: grade point average (GPA), AHPVT (the version Peabody Picture Vocabulary Test [PPVT] designed for Add Health), aggressive behavior, and depression. Our hypothesis is supported in analyses among same-sex friends (not among different-sex friends) for GPA, aggressive behavior, and AHPVT.
（1）观察到朋友之间在某些特质和行为上的相似性；（2）有证据表明这些特质和行为中的许多都有遗传成分。使用来自青少年健康全国纵向研究（Add Health）的同卵双胞胎（MZ）、异卵双胞胎（DZ）、亲兄弟姐妹及其最好的朋友对这一假设进行了检验。针对4种个体特质或行为，即平均绩点（GPA）、AHPVT（为Add Health设计的皮博迪图片词汇测试[PPVT]版本）、攻击性行为和抑郁，研究了MZ双胞胎的朋友之间的相似性是否大于DZ双胞胎和亲兄弟姐妹的朋友之间的相似性。在对同性朋友（而非异性朋友）进行的GPA、攻击性行为和AHPVT分析中，我们的假设得到了支持。
