Typically, rhesus mothers begin rejecting their infants' attempts to nurse when the infants are approximately three months of age in order to begin the process of weaning. A small subgroup of mothers begin rejecting their infants earlier, at one or two months of age, typically before infants seek and maintain independence from their mother. The effects of this early maternal rejection on the development of infants and some potential factors that contribute to premature maternal rejection were explored in this study. Infants who were rejected early were hypothesized to subsequently spend less time in positive contact with their mother, have lower activity levels, were groomed less by their mother and, as a consequence of the maternal rejections, display a higher frequency of aggression toward other group members when compared to infants experiencing maternal rejection after the age-typical, three months of age. Mothers who were primiparous and/or had a poor early-rearing experience were hypothesized to be more likely to reject their infants prematurely. Consistent with these hypotheses, infants who were rejected early spent less time on their mother's ventrum and were groomed less by their mother, suggesting that early maternal rejection may lead to less positive mother-infant interactions and a more distant mother-infant relationship. Infants rejected early were also more likely engage in aggression. Given the punitive nature of the maternal rejection, the results suggest that aggression is transmitted from mother to infant through their interactions. Prematurely rejected infants were found to spend significantly more time in a passive, withdrawn behavioral state. When assessing the causes of premature rejections, primiparous mothers were not more likely to prematurely reject their infants, indicating that premature rejection was not simply a lack of experience with an infant. There was evidence that the mothers engaging in early rejection had poor early-rearing experiences, with surrogate-peer-reared mothers showing more early rejections than those who were reared by an adult female, and with mothers who were peer-reared having higher rates of rejection overall. The present results suggest that early rejection is associated with more difficult mother-infant relationships and may lead to increased likelihood of aggression in infants.



College and Department

Family, Home, and Social Sciences; Psychology



Date Submitted


Document Type





aggression, mother-infant relationship, maternal care, rejection, rhesus macaques

Included in

Psychology Commons