learning through social interactions is essential for many primates to be able to predict the social consequences of behavior directed toward live partners, to acquire appropriate communication skills, to care for infants properly, and to recognize predators. It is not clear, however, what types of experience will foster social competence or other aspects of species-normal behavior. Can cross-species fostering substitute for normal social environments, or does a cross-fostered animal lose some of its species-typical behavior (Seyfarth and Cheney 1997)? To what extent is housing with adult males, females other than the mother, and immature animals of both sexes necessary or sufficient for normal development? Can infants be successfully reared with aged adults or peers, thereby freeing young adults for rebreeding?
Although the importance of social stimulation during infancy is well established, considerably less is known about the influence of social contact during the juvenile and adolescent stages of development. The issue is important, inasmuch as primates are often moved from their familiar social groups and housed elsewhere. More information is also needed on the adaptation of wild-born animals to captivity and on how to prepare captive animals for release to free-ranging conditions or to the wild. We also need to know whether primates reared in free-ranging situations require strategies for promoting psychological well-being that are different from those required for animals born and reared in captivity.
Several characteristics of individual animals can influence their psychological well-being in captive settings. Age and sex play major roles. It is important to determine what factors are necessary for the development of social competence in males and females. This information, for various species, might have important implications for the long-term success of captive breeding groups. One could argue that animals that fail to develop social competence for life in a social group and successful reproduction and parenting are damaged animals. The extent to which such animals are psychologically damaged and the importance of these failures require further exploration. Likewise, we need to understand the effects of age on psychological well-being and to determine effective strategies for maintaining both very young and very old animals in a state of well-being.
Cage design can be important in fostering well-being in captive primates. To that end, research is needed to evaluate the effects of particular caging materials (plastic, wood, and metal) and cage designs (dimensions and cage configuration) in eliciting species-typical patterns of behavior in the different species of primates maintained in captivity (e.g., Crockett and Bowden 1994; Shimoji and