Social sources of information about foods are apparently important in the development of diet patterns in young rabbits and rats (

To determine whether young capuchin monkeys, Cebus apella, selectively interacted with others concerning novel foods, 11 infants (4.5–12 months) living in two groups were observed following presentation of familiar or novel foods. Foods were presented either to the whole group or to infants in a section of the home cage to which only they had access. Infants showed more frequent interest in others’ food and picked up foods more frequently when foods were novel, and they tended to eat novel foods more frequently than familiar foods. The pattern was the same whether the foods were presented to the group or only to infants. Infants expressed interest in others’ novel foods equally often before and after sampling these foods themselves. The frequency of interest in others’ food correlated positively with age. It is concluded that acceptance of novel foods in these monkeys occurs readily regardless of socially provided information about edibility. Social interactions do not appear to make important contributions to acceptance of novel foods by infant capuchin monkeys. Social sources of information about foods are apparently important in the development of diet patterns in young rabbits and rats (Galef 1976; R. Hudson, A. Bilko & V. Altbacker, unpublished data) and the acceptance of novel foods among older animals. Galef (1993) argued that neophobia towards foods, coupled with readier acceptance of a novel food following exposure to a conspecific that has previously eaten the food, reduce the risk of enlarging the diet for a generalist omnivore such as the rat. In this view, social facilitation of feeding ought to be more evident with novel foods than with familiar foods. Acceptance of novel foods in older juvenile and adult capuchin monkeys, Cebus apella, has been shown to fit the pattern predicted by Galef (1993). Consumption of novel foods was enhanced when individuals ate with others compared to when they encountered the foods while alone, but social context did not affect consumption of familiar foods (Visalberghi & Fragaszy 1995). There are many striking images and reports from field settings of primate infants examining and sampling others’ food, and a few reports document the frequency of such interactions (e.g. King 1994). A general assumption is that an infant primate’s experiences with foods while near the mother or other kin, in particular, and social partners in general, have a formative role in its selection of foods later on (e.g. Fedigan 1982; Box 1984; Watts 1985). The linked assumptions that infants are learning something from these interactions, however, and that they engage in them for this purpose, warrant closer scrutiny (e.g. Milton 1993). First, few systematic data relate infants’ interactions with others during feeding to their subsequent feeding behaviour. Second, one cannot know whether the foods so examined are novel to the infant, and so one cannot conclude that infants learn that some new item is edible from interacting with others (King 1994). Finally, we do not know whether infants engage in these interactions selectively, in a manner conducive to learning from more knowledgeable others, or merely do so opportunistically with any individual holding an item of interest. The process could occur randomly, uninfluenced by the young animal’s competence at feeding itself or what was being eaten, or young animals could selectively approach others with unfamiliar items or items that it has difficulty obtaining itself (King 1994). King argued from field data that young savannah baboons, Papio cynocephalus, selectively approach and interact with adults feeding upon favoured and difficult foods, and that these actions might benefit infants’ current and future foraging success. As she notes, however, her field data are not sufficient to make a strong test of the hypotheses. We took up some of these issues in a study of infant capuchin monkeys in captivity. In captivity, transfers between capuchin monkeys of food as well as other objects of interest, particularly between others and infants, are commonplace and occur in an atmosphere of tolerance (Westergaard & Fragaszy 1985; Fragaszy & Visalberghi 1989; de Waal et al. 1993; Furbush 1994). If the foods obtained through interactions with others were novel, young individuals could learn about the acceptability of foods from others in their group through food-related interactions and socially mediated transfers of food. But do they engage in these activities selectively to learn about novel foods? Is acceptance of a novel food dependent upon, or enhanced by, these kinds of interactions? In this study, we investigated whether young capuchin monkeys show selectivity in feeding and in inspecting others’ novel foods, in line with King’s (1994) model of the active role of infants in acquiring information about foods drawn from her observations of baboons. We expected that young capuchin monkeys would show some avoidance of novel foods. We also expected that infant capuchins would show more interest in others’ food when encountering a novel food than a familiar food (as captive capuchin monkeys do with other novel items; e.g. Visalberghi 1988). Furthermore, and relevant to King’s model, if infants seek information from adults about acceptability of a potential food, infants should (1) seek information from others about novel foods, through approach and interaction with food holders, more often before than after first eating them, and (2) eat fewer novel foods, or eat them later, when the foods are available only to infants than when they are available to all members of the group. Finally, we considered the relation between age of the infant and extent of interest in others’ food. Older infants, approaching weaning and partially responsible for feeding themselves, could be expected to have greater interest in others’ food than younger infants, if interest is related to the functional problem of knowing whether something is edible. If no relation between age and interest exists, then interest is not likely to be related to youngsters’ growing self-reliance in feeding.