Ignorance is no excuse: Moral judgments are influenced by a genetic variation on the oxytocin receptor gene

► We investigated the effect of a genetic variant on the OXTR gene in moral judgments. ► Participants rated the blameworthiness of different kinds of harm. ► Participants were grouped into C+ and C− carriers of the OXTR rs2268498. ► C+ carriers rated accidentally committed harm as more blameworthy than C. Perspective-taking has become a main focus of studies on moral judgments. Recent fMRI studies have demonstrated that individual differences in brain activation predict moral decision making. In particular, pharmacological studies highlighted the crucial role for the neuropeptide oxytocin in social behavior and emotional perception. In the present study N=154 participants were genotyped for a functional polymorphism (rs2268498) in the promoter region of the OXTR gene. We found a significant difference between carriers and non-carriers of the C-allele in exculpating agents for accidental harms (F(1,152)=11.49, p=.001, η2=.07) indicating that carriers of the C-allele rated accidentally committed harm as significantly more blameworthy than non-carriers. This is the first study providing evidence for a genetic contribution to moral judgments.