The Oxytocin Receptor (OXTR) Contributes to Prosocial Fund Allocations in the Dictator Game and the Social Value Orientations Task

Abstract

BackgroundEconomic games observe social decision making in the laboratory that involves real money payoffs. Previously we have shown that allocation of funds in the Dictator Game (DG), a paradigm that illustrates costly altruistic behavior, is partially determined by promoter-region repeat region variants in the arginine vasopressin 1a receptor gene (AVPR1a). In the current investigation, the gene encoding the related oxytocin receptor (OXTR) was tested for association with the DG and a related paradigm, the Social Values Orientation (SVO) task.Methodology/Principal FindingsAssociation (101 male and 102 female students) using a robust-family based test between 15 single tagging SNPs (htSNPs) across the OXTR was demonstrated with both the DG and SVO. Three htSNPs across the gene region showed significant association with both of the two games. The most significant association was observed with rs1042778 (p = 0.001). Haplotype analysis also showed significant associations for both DG and SVO. Following permutation test adjustment, significance was observed for 2–5 locus haplotypes (p<0.05). A second sample of 98 female subjects was subsequently and independently recruited to play the dictator game and was genotyped for the three significant SNPs found in the first sample. The rs1042778 SNP was shown to be significant for the second sample as well (p = 0.004, Fisher's exact test).ConclusionsThe demonstration that genetic polymorphisms for the OXTR are associated with human prosocial decision making converges with a large body of animal research showing that oxytocin is an important social hormone across vertebrates including Homo sapiens. Individual differences in prosocial behavior have been shown by twin studies to have a substantial genetic basis and the current investigation demonstrates that common variants in the oxytocin receptor gene, an important element of mammalian social circuitry, underlie such individual differences.

Candidate gene studies and the quest for the entrepreneurial gene

“…Indeed, there are numerous examples of smallscale candidate gene studies that report significant associations with behavioral traits that could not be replicated. For instance, Israel et al (2009) report an association between a variant of the OXTR gene and the dictator game. Apicella et al (2010) fail to replicate this association.…”

“…Obviously, the reported association would not have reached the accepted genome-wide significance level of p \ 5 9 10 -8 . Associations are often reported to be false positives if a set of candidate genes is selected, while not all relevant genes and SNPs are considered (e.g., Apicella et al 2010;Becker et al 2007;Israel et al 2009;Lang et al 2004;Lesch et al 1996;Vormfelde et al 2006). …”

Toward a Radically Embodied Neuroscience of Attachment and Relationships?

“…For example, oxytocin receptor gene (OXTR) variation is associated with prosocial behavior (Israel et al, 2009), empathy and stress reactivity (Rodrigues et al, 2009), pair bonding (Walum et al, 2011), parenting behavior (Bakermans-Kranenburg and van Ijzendoorn, 2011), emotional loneliness (Lucht et al, 2009), and functional links between hypothalamic and limbic system activity in emotional face processing (Tost et al, 2010). Epigenetic variation in methylation of the OXTR gene is similarly associated with neural responses to ambiguous social stimuli (Jack et al, 2012), autism and callous-unemotional traits (Gregory et al, 2009;Kumsta et al, 2013).…”

Association of Genetic Variation in the Promoter Region of OXTR with Differences in Social Affective Neural Processing

“…Independent studies have reported evidence that variation in OXTR increases susceptibility for ASC [36][37][38][39][40][41], although there has been some heterogeneity in these findings [42]. Persons diagnosed with ASC often exhibit gross impairments in social functioning [43]. Furthermore, OXTR risk variants for ASC have been associated with individual differences in healthy populations in social behaviours of trust [42] and empathy [44,45].…”