The role of oxytocin receptor gene variants in appetitive aggression : A study in a South African male sample

Abstract

Chronic exposure to trauma and violence can promote aggressive behavior. Oxytocin and variants in the oxytocin receptor (OXTR) gene may play a role in the etiology of proactive, that is, goal‐oriented instrumental aggression, or reactive aggression, which typically occurs in response to emotionally triggering situations. The current study builds on previous findings that experienced and witnessed trauma in childhood predicts higher levels of appetitive aggression, a form of proactive aggression characterized by the enjoyment of participating in violent behavior. The current study explores the role of OXTR rs2254298 and rs53576 variants in appetitive and reactive aggression. Adult males living in Cape Town, South Africa, and at risk for violent behavior completed the Appetitive Aggression Scale (AAS) and Buss–Perry Aggression Questionnaire (BPAQ). OXTR rs2254298 and rs53576 were successfully genotyped via restriction fragment length polymorphism (RFLP) analysis in 238 and 239 participants, respectively. Regression analysis showed that rs2254298 G/G and A/G genotypes and the rs53576 A/G genotype were significantly associated with lower AAS scores ( p < .001) compared to the A/A genotype. Additionally, genotype interaction analyses conducted in 232 participants, found that the combination of rs2254298 A/G and rs53576 G/G genotypes produced opposite effects on appetitive and reactive aggression. Specifically, this combination was associated with a 0.29‐point increase in AAS scores ( p = .032) and a 0.13‐point decrease in BPAQ scores ( p = .037) when compared to A‐allele homozygosity for both variants. These results suggest that genetic variation in a signaling system involved in influencing environmental and social salience may contribute to appetitive aggression.