Preferences towards novel foods in Cebus apella: the role of nutrients and social influences.

Information on the process of preference acquisition towards novel foods in nonhuman primates is lacking. This study aims to assess (1) whether nutrient and energy contents affect preferences towards novel foods encountered repeatedly by individuals when alone, (2) whether these preferences change after additional encounters with the novel foods, and (3) if the change is sensitive to social influences. We presented seven novel foods to 26 socially housed tufted capuchins. In Phase 1, each subject was presented individually with the 21 possible binary combinations of the seven novel foods. Afterwards, during treatment, 13 subjects received the novel foods ad libitum with their group members (social condition) and 13 subjects received the foods individually (individual condition); subjects assigned to the individual and social conditions had shown similar food preferences in Phase 1. Finally, in Phase 2, each subject was presented again with 21 binary choices between each of the novel foods. In Phases 1 and 2, the number of times each food was chosen differed among foods. In Phase 1, food preference correlated positively with glucose and fructose and negatively with total fiber content. In Phase 2, irrespective of social or individual prior experience in the treatment condition, food preference changed and became correlated with total energy content. Our results broaden the findings already available for familiar foods by demonstrating that individual experience based on the feedback obtained from novel foods guides the establishment of preferences towards them. Moreover, individual experience is sufficient to determine food preferences similar to those individuals may acquire when together with group members eating the same foods.