This study tested the hypothesis that differences in parenting styles between two captive populations of rhesus macaques, one living in the UK (Madingley) and the other in the USA (Yerkes), are associated with differences in the degree to which social interactions with other group members pose a risk to infants. Twenty-eight mother–infant dyads, 17 living at Madingley and 11 at Yerkes, were observed for 24 h during the first 12 wks of infant life. Mother–infant dyads living at Madingley spent a higher percentage of time in contact than those living at Yerkes. The Madingley mothers also restrained and retrieved their infants more often, and rejected them less often than the Yerkes mothers. Consistent with the prediction, the protective parenting style of the Madingley mothers was associated with higher frequency of infant kidnapping and higher risk of infant harassment from other group members. Interpopulation differences in risks to infants and parenting styles are likely to be the result of differences in social density in the two environments rather than differences in the matrilineal structure of the two populations.