title: The association between oxytocin and social capital.
abstract: BACKGROUND
  Oxytocin is known to be related to social behaviors, including trust. However, few studies have investigated the association between oxytocin levels and social capital. Thus, we tested the hypothesis that endogenous oxytocin levels are positively associated with social capital. We also considered whether the association differed across gender because previous studies have shown differential effects of OT on social behaviors depending on gender.
  
  
  METHODS
  We recruited a convenience sample of 50 women and 31 men in Japan via community sampling from whom we obtained urine sample with which to measure oxytocin levels. Individual-level cognitive social capital (social trust and mutual aid) and structural social capital (community participation) were assessed using a questionnaire. We used multivariate regression, adjusted for covariates (age, number of children, self-rated health, and education), and stratified by gender to consider associations between oxytocin and social capital.
  
  
  RESULTS
  Among women, oxytocin was inversely associated with social trust and mutual aid (p<0.05). However, women participating in only 1 organization in the community showed higher oxytocin than women who participated in either no organizations (p<0.05) or 2 or more organization (i.e. inverse-U shape association). Among men, no association was observed between oxytocin and either form of cognitive and structural social capital.
  
  
  CONCLUSIONS
  Women who perceived low cognitive social capital showed higher oxytocin levels, while structural social capital showed inverse-U shape association with oxytocin. No association between oxytocin and social capital was found among men. Further study is needed to elucidate why oxytocin was inversely associated with cognitive social capital only among women.
authors.affiliation: Department of Social Medicine, National Research Institute for Child Health and Development, Tokyo, Japan. fujiwara-tk@ncchd.go.jp
authors.forename: Takeo
authors.initials: T
authors.lastname: Fujiwara
authors.forename: Laura D
authors.initials: LD
authors.lastname: Kubzansky
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kawachi
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D010121:Oxytocin / Q000652:urine*; D012737:Sex Factors; D012919:Social Behavior; D035502:Trust / Q000523:psychology
chemical_list: D010121:Oxytocin