Effects of reducing the mother's radius of action on the development of mother-infant relationships in longtailed macaques

Abstract

Abstract. Longtailed macaque, Macaca fascicularis, mothers, but not their infants, were limited in their radius of action to a small part of the harem-group cage. The behaviour of infants and the mother-infant relationship in these restrained dyads and in unrestrained dyads were compared during the first half year of life. Restraining the mother had no effect on the mother-infant relationship. Furthermore, there was only one effect on the infants' development, namely that infants of restrained mothers were on average 11 weeks older when they went beyond arm's reach of their mothers. This retardation in development of these infants' radius of action can be explained by infants being unwilling to enter the unfamiliar environment which could not be explored with the mother nearby.