Several studies in human medicine have focused on oxytocin receptor gene (OXTR) polymorphisms and their role in social behaviors. This study examined the relationship between OXTR polymorphisms in cats and owner assessment of the cats’ behaviors. Cats were either pets in private homes (n = 56) or belonged to 1 of 6 cat cafés (n = 38) where customers can freely interact with cats. Owners completed a detailed questionnaire that categorized cat behaviors into 4 groups: openness (playful, inquisitive, and curious), friendliness (adaptable, calm, and friendly), roughness (irritable, dominant, forceful, and moody), and neuroticism (vigilant, nervous, and fearful). When genetic data from the cats were analyzed, the investigators found 3 single nucleotide polymorphisms in the OXTR of cats; 1 was significantly associated with roughness. Younger cats showed higher openness scores and older cats demonstrated higher roughness scores. The authors conclude these findings may have implications for animal welfare, as genetic testing could be used to predict compatibility in cat–cat and cat–human relationships.