Owner-reported personality assessments are associated with breed groups but not with oxytocin receptor gene polymorphisms in domestic dogs (Canis familiaris)

Abstract

Variation in the oxytocin receptor (OXTR) gene has been linked to dog social behavior in some studies, whereas others have failed to replicate this relationship (in dogs and other species). Ratings of observed behavior are often used to assess personality; however, owner-based behavior and personality assessments have been shown to be comparably consistent. The relationship between OXTR gene variation and behavior as measured by owner-based personality questionnaires has yet to be explored in dogs. The aims of our present study were 3-fold: (1) to investigate the relationship between 2 OXTR single nucleotide polymorphisms (SNPs) (rs8679684 and 19131AG) and 3 owner-based behavior and personality measures in dogs (the Monash Canine Personality Questionnaire-Revised, a history of aggression questionnaire, and an eagerness to please scale), (2) to explore the relationships of personality assessments and OXTR polymorphisms with genetic breed clusters, purebred versus mixed breed status, and how the dog was acquired (shelter vs. other means), and (3) to examine the relationships among the 3 owner-based assessments. We found no relationship between any of the 3 personality measures and genotype at either SNP. This may be because of the relationships between OXTR gene SNPs and behaviors being breed specific, in which case our genetically varied sample would not detect them. In line with kennel club breed descriptions and prior research, herding breeds scored higher in eagerness to please than scent hound breeds, and scent hounds' training focus scores were lower than those of both herding and working breeds. Purebred and mixed breed dogs did not score differently in any of the 3 personality assessments, and dogs adopted from shelters were rated lower in extraversion and eagerness to please than those acquired by other means, suggesting that early shelter experience may affect adult behavior. Dogs with no history of aggression toward household members, unfamiliar children, unfamiliar men and women, and unfamiliar dogs scored higher in amicability, and eagerness to please scores were positively correlated with training focus and amicability. These personality measures appear to evaluate different facets of the same personality concepts. Future research on OXTR gene variation in dogs should be mindful of the possibly limited implications of behavioral assessments that are context specific.