Abstract # 55:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


A. Bassett1, M. L. Schwandt2, S. G. Lindell2, C. S. Barr2, S. J. Suomi3 and J. D. Higley1
1Brigham Young University, Department of Psychology, Provo, UT 84602, USA, 2NIH Animal Center, NIAAA, LCTS, Poolesville, MD 20837, 3NIH Animal Center, NICHD, LCE

Typically, rhesus mothers begin rejecting their infants’ attempts to nurse when the infants are approximately three months of age. A small subgroup of mothers reject their infants earlier (1-2 months of age). The effects of premature maternal rejection on the development of infants are explored in this study. Infants [N=177] were behaviorally observed in their home cages across the first 6 months of life. Behavior scores collected from the infant’s home cage were analyzed using mixed design repeated-measures ANOVA, with early vs normal timing in rejection as the between groups factor [α=0.05]. It was hypothesized that infants who were rejected early would spend less time on their mother, be groomed less by their mother and exhibit more aggression. Consistent with our hypotheses, infants who were rejected early were found to spend less time on their mother’s ventrum [p=0.05] and were groomed less by their mother [p<0.1], suggesting that early maternal rejection may lead to less positive mother-infant interactions and a more distant mother-infant relationship. Given the punitive nature of the maternal rejection, it is not surprising that the early rejected infants exhibited significantly more aggression to their cagemates. We conclude that aggression is transmitted from mother to infant in their interactions; alternatively, aggressive tendencies may be inherited by the infant from its mother.