LeClair, J., Sasaki, J. Y., Ishii, K. (石井敬子), Shinada, M. (品田瑞穂), Kim, H. S. (2016). Gene–culture interaction: influence of culture and oxytocin receptor gene (OXTR) polymorphism on loneliness. 遺伝子と文化の相互作用：文化とオキシトシン受容体遺伝子の多相性が孤独感に及ぼす影響 Culture and Brain, 1-17.
Previous research has shown that culture and genes can interact to influence social behaviors. Variation of the oxytocin receptor gene (OXTR) rs53576 polymorphism has been linked to differential susceptibility to cultural influences with genetically susceptible individuals showing more culturally typical behaviors. The present research focuses on a psychological outcome of such behaviors, specifically loneliness, which is an outcome related to well-being. We also considered attachment style as a mediator for the interaction between culture and OXTR genetic variation on loneliness. Previous gene–culture interaction research shows that G-allele carriers may be genetically predisposed to show more culturally typical behaviors and psychological tendencies, compared to A-allele carriers. Thus, we expected that genetically susceptible Japanese would show a more avoidant attachment style (a pattern more common in Japan), while susceptible Americans would show a more secure attachment style (a pattern more common in the U.S.). In both cultures, we expected that greater avoidant relationship tendencies would predict greater loneliness. Participants (217 American and 153 Japanese students) completed scales to measure loneliness and attachment style, and provided saliva for genotyping. As predicted, culture moderated the link between genetic susceptibility and loneliness, with G-allele Americans showing less loneliness than A-allele carriers. Further, the link was mediated by attachment style. Our study extends existing research by showing that gene–culture interactions on relationship patterns have consequences for psychological well-being outcomes.