Variation in the oxytocin receptor gene is associated with pair-bonding and social behavior

Abstract

Background: In specific vole and primate species the neuropeptide oxytocin plays a central role in the regulation of pair-bonding behavior. Here we investigate the extent to which genetic variants in the oxytocin receptor gene (OXTR) are associated with pair-bonding and related social behaviors in humans.

Methods: We first genotyped twelve single nucleotide polymorphisms (SNPs) in the TOSS (Twin and Offspring Study in Sweden) (n = 2309) and the TCHAD (Swedish Twin Study of Child and Adolescent Development) (n = 1240), comprising measures of self-reported pair-bonding behavior. In the TOSS sample we further investigated one of the SNPs for measures of marital status and quality. Moreover, in the TCHAD sample we explored the longitudinal relationship between precursors of pair-bonding during childhood and subsequent behavior in romantic relationships. Finally, in the TCHAD study and in the Child and Adolescent Twin Study of Sweden (CATSS) (n = 1771), the association between the same SNP and childhood behaviors was investigated.

Results: One SNP (rs7632287) in OXTR was associated with traits reflecting pair-bonding in women in the TOSS and TCHAD samples. In girls the rs7632287 SNP was further associated with childhood social problems, which longitudinally predicted pair-bonding behavior in the TCHAD sample. This association was replicated in the CATSS sample in which an association between the same SNP and social interaction deficit symptoms from the autism spectrum was detected.

Conclusion: These results suggest an association between variation in OXTR and human pair-bonding and other social behaviors, possibly indicating that the well-described influence of oxytocin on affiliative behavior in voles could also be of importance for humans.

Figure 1. Overview of the order of analysis, samples and measures used to investigate associations between oxytocin receptor gene (OXTR) polymorphisms and pair-bonding behaviour as well as childhood deficits in social behaviours

Firstly, associations between 12 SNPs in the oxytocin receptor gene (OXTR) and measures of pair-bonding were investigated in the TCHAD and TOSS samples, comprising men and women in romantic relationships (see Tables 2 and 3 for the results from these analyses ). Secondly, the SNP positively associated with pair-bonding behavior in women in the first step (rs7632287) was further studied in relation to marital crisis and measures of marital quality as perceived by spouses in the TOSS sample (Table 4a,b). Thirdly, the relation between behaviors in young girls and adult pair-bonding behavior was explored using the longitudinal design in TCHAD (Table 4c). The CBCL subscale social problems at age 8–9 was revealed to predict pair-bonding behavior in adulthood. Fourthly, the rs7632287 SNP was studied in relation to the social problems scale in TCHAD. The CBCL social problems scale has previously been shown to be associated with measures of the autism spectrum (65) and in the final step the rs7632287 SNP was studied in relation to symptoms of autism assessed in an additional sample, CATSS (Table 5). See text for further details and references regarding the samples and the different measures. Sample names are in bold text. RQS=Relationship Quality Survey, PBS=Partner Bonding Scale, CBCL=Child Behavior Checklist, A-TAC= the Autism—Tics, AD/HD, and other Comorbidities inventory.