Taste perception and food choices in capuchin monkeys and human children.

Despite more than 40 million years of independent evolution, capuchin monkeys and human children share several features that make a comparison in the domain of feeding behaviour interesting. As with humans, capuchin monkeys have a long life span and an extended infancy period; moreover, they are omnivorous and food neophobic. In both species, taste provides an immediate and powerful feedback when selecting foods. In humans, acceptance and rejection responses are evident beginning in early infancy, before experiencing any consequences from the ingestion of sweet or bitter substances. Similarly, capuchins initially prefer novel foods with a high sugar content that is readily perceived through taste. However, after repeated encounters with these foods, capuchins change their preferences, responding to the feedback coming from the foods' energy content, in order to maximize the net gain of energy. Also in children, positive consequences of the ingestion of a food can be associated with the flavour of that food and can increase its consumption. Preschool children learn to prefer food with a high caloric content over food with a low caloric content and use different flavours as immediate cues to distinguish foods. Another factor influencing the consumption of a novel food is how often it is encountered. For capuchins, a food remains unfamiliar only for the first few encounters. Similarly, children's neophobic response decreases with repeated exposures to novel foods. Furthermore, in both species social influences may help to overcome food neophobia and to accelerate the acceptance of novel foods into the diet. In conclusion, we argue that capuchin monkeys provide a good model for investigating the factors affecting the acquisition of diet in human children.