Functions of social learning about food: a causal analysis of effects of diet novelty on preference transmission

Abstract. A naive rat (an observer) that interacts with a recently fed conspecific (a demonstrator) subsequently exhibits a substantially enhanced preference for whatever food its demonstrator ate. In the present series of experiments, it was found that: (1) demonstrator rats that ate foods unfamiliar to their respective observers influenced the food preferences of observers more than did demonstrator rats that ate foods familiar to their observers and (2) demonstrator rats that had eaten both a food unfamiliar to observers and a food familiar to observers induced greater preference for the former than for the latter. These results suggest that social enhancement of flavour preferences does not reinforce rats' inherent tendency to prefer familiar foods. Rather, social enhancement of flavour preference biases rats to incorporate unfamiliar foods into their feeding repertoires. Because (1) unfamiliar substances that conspecifics are eating are more likely to be beneficial than are other unfamiliar substances in the environment and (2) social interaction increases the probability that rats will ingest unfamiliar substances that conspecifics are eating, socially induced changes in diet preference should reduce potential costs of increasing dietary breadth.