It is long known that inbreeding increases the detrimental effects of recessive sequence variants in “Runs of Homozygosity” (ROHs). However, although the phenotypic association of ROH has been investigated for a variety of traits, the statistical power of the results often remains limited as a sufficiently high number of cases are available for only a restricted number of traits. In the present study, we aim to analyze the association of runs of homozygosity with the trait “in-group ethnic favoritism”. This analysis assumes that if ethnic identity is important for an individual, that individual may tend to marry more frequently within their own group and therefore ROH are expected to increase. We hypothesize that an attitude preferring one’s own ethnic group may be associated with a stronger tendency of inbreeding and, as a result, with more and longer ROHs. Accordingly, we investigated the association between the attitude to someone’s own ethnicity and ROH, using the Wisconsin Longitudinal data (WLS, total N ~ 9000) as discovery data set and the Brisbane Twin data as replication data set (N ~ 8000). We find that both the number as well as the total length of homozygous segments are significantly positively associated with “in-group ethnic favoritism”, independent of the method used for ROH calculation.

众所周知，近亲繁殖会增加“纯合性运行”(ROH) 中隐性序列变异的不利影响。然而，尽管已经针对各种性状研究了 ROH 的表型关联，但结果的统计功效通常仍然有限，因为只有有限数量的性状有足够多的病例可用。在本研究中，我们旨在分析纯合子运行与“群体内种族偏爱”特征的关联。该分析假设，如果种族身份对个人很重要，则该个人可能倾向于在自己的群体内更频繁地结婚，因此预期 ROH 会增加。我们假设偏爱自己种族的态度可能与更强烈的近亲繁殖趋势有关，因此，具有更多和更长的 ROH。因此，我们使用威斯康星纵向数据（WLS，总 N ~ 9000）作为发现数据集，使用布里斯班双胞胎数据作为复制数据集（N ~ 8000），调查了对某人自己种族的态度与 ROH 之间的关联。我们发现纯合片段的数量和总长度都与“群体内种族偏爱”显着正相关，与用于 ROH 计算的方法无关。