Abstract # 38:

Scheduled for Thursday, June 19, 2008 05:00 PM-07:00 PM: Session 4 (Ball Rooms A and B) Poster Presentation

Development of infant-mother independence in Macaca mulatta housed in modified nuclear-family housing

E. K. Mallott, M. F. S. X. Novak, K. L. Robbins, C. S. Ionica, M. L. Miller, E. A. Kerschner and S. J. Suomi
NIH, Laboratory of Comparative Ethology, National Institute of Child Health and Human Development, NIH Animal Center, Poolesville, MD 20837, USA
     The earliest age at which infant rhesus macaques (M. mulatta) voluntarily depart their mother is an important developmental indicator. As part of a study on maternal-fetal to maternal-infant continuities, we reared mother-infant pairs nonsocially in modified nuclear-family housing: a single cage with an adjoining infant-only area to promote species-typical infant development. Willingness of the infant and mother for the infant to enter the infant-only side of the cage may be used as a measure of development of mother-infant independence. In order to generalize mother-infant interactions in single cages to more species-typical experiences, we compared the age when infants were first observed in the infant-only side (n=8) with the age when infants were first observed >5 meters from the mother in a field station [n=17; independent t-tests, a=0.05]. Larger enclosures and social support might cause greater infant independence at younger ages. Conversely it is possible that small caging enclosures would encourage infant independence due to limited infant control of contingencies in this setting. Nonsocial mother-reared infants entered the infant-only area at M=46.6 (SD=17.9; range 19-72) days, while infants from the field station were first observed >5 meters from their mother at M=56.0 (SD=20.2) days (ns). Age at first entering the infant-only area of modified nuclear-family housing may indicate the development of individual differences in mother-infant independence. Research supported by intramural research program of the NICHD at NIH.