Gyuris Petra, Kozma Luca, Kisander Zsolt, Láng András, Ferencz Tas, Kocsor Ferenc
Institute of Psychology, Faculty of Humanities, University of Pécs, Pécs, Hungary.
Institute of Behavioural Sciences, Medical School, University of Pécs, Pécs, Hungary.
Front Psychol. 2020 Jun 9;11:993. doi: 10.3389/fpsyg.2020.00993. eCollection 2020.
In "patchwork" families, full siblings, maternal and paternal half-siblings, and non-related children are raised together, and sometimes, genetically related children are separated. As their number is steadily growing, the investigation of the factors that influence within-family relations is becoming more important. Our aim was to explore whether people differentiate between half- and full-siblings in their social relations as implied by the theory of inclusive fitness, and to test whether co-residence or genetic relatedness improves sibling relations to a larger extent. We administered the Sibling Relationship Questionnaire to 196 individuals who were in contact with full-, half-, or step-siblings in their childhood. We built Generalized Linear Mixed Models models to test for the effects of relatedness and co-residence on sibling relations. In general, a higher degree of relatedness was associated with better sibling relations, but only among those who did not live together during childhood. Co-resident siblings' overall pattern of relation quality was not influenced by the actual level of genetic relatedness. In contrast to this, full siblings reported having experienced more conflicts during childhood than half-siblings, possibly resulting from enhanced competition for the same parental resources. The results suggest that inclusive fitness drives siblings' relations even in recent industrial societies. However, among individuals who live together, the effect of relatedness might be obscured by fitness interdependence and the subjective feeling of kinship.
在“拼凑式”家庭中，同父同母的亲兄弟姐妹、同父异母或同母异父的半同胞兄弟姐妹以及无血缘关系的孩子共同成长，有时，有血缘关系的孩子还会被分开。由于这类家庭的数量在稳步增加，研究影响家庭内部关系的因素变得越发重要。我们的目的是探讨人们在社会关系中是否会像广义适合度理论所暗示的那样区分半同胞和全同胞兄弟姐妹，并检验共同居住或基因相关性在更大程度上是否能改善兄弟姐妹关系。我们对196名在童年时期与全同胞、半同胞或继兄弟姐妹有过接触的人进行了兄弟姐妹关系问卷调查。我们构建了广义线性混合模型来检验亲属关系和共同居住对兄弟姐妹关系的影响。总体而言，亲属关系程度越高，兄弟姐妹关系越好，但这仅适用于童年时期未共同生活的人。共同居住的兄弟姐妹关系质量的总体模式不受实际基因相关程度的影响。与此相反，全同胞兄弟姐妹报告称在童年时期比半同胞经历了更多冲突，这可能是由于对相同父母资源的竞争加剧所致。研究结果表明，即使在现代工业社会，广义适合度也在驱动着兄弟姐妹之间的关系。然而，在共同生活的个体中，亲属关系的影响可能会被适合度相互依赖和亲属关系的主观感受所掩盖。
