Ohtsubo et al. (2014)

Ohtsubo, Y.(大坪庸介), Matsunaga, M., Komiya, A.(小宮あすか), Tanaka, H.(田中大貴), Mifune, N.(三船恒裕), & Yagi, A.(八木彩乃) (2014).
Oxytocin receptor gene (OXTR) polymorphism and self-punishment after an unintentional transgression.
Personality and Individual Differences, 69, 182-186.
doi: 10.1016/j.paid.2014.05.033    
The present study investigated a genetic underpinning of human reconciliation. Recent research has shown that people tend to inflict self-punishment as part of a repertoire of reparative acts. Since empathy generally facilitates reparative acts, we hypothesized that there exists an association between an empathy-related genetic variation, a single nucleotide polymorphism (SNP) in the oxytocin receptor (OXTR) gene (rs53576 A vs. G), and the tendency toward self-punishment. Participants played a modified version of the dictator game, in which they made an unfair allocation unintentionally. They then had the opportunity to punish themselves by reducing some portion of their monetary reward. The results showed that the participants with the GA or GG genotype, compared to the participants with the AA genotype, were more likely to engage in self-punishment after making the unfair allocation unintentionally. This effect was not mediated by self-critical feelings (guilt and shame) associated with the unfair allocation. The present study suggests that the OXTR polymorphism is associated with a human reconciliatory tendency.