The role of conformity in foraging when personal and social information conflict

There is currently considerable interest in the interplay between personal and social information in decision-making processes. Two experiments are presented exploring the relative use of prior personal information and subsequent social information in foraging decisions of guppies. Experiment 1 tested the assumption that when the use of information acquired through personal experience is not costly, conflicting social information will be ignored. The assumption was confirmed because, when given a choice between feeding at two food patches, at one of which they had previously seen conspecifics feed, individual fish with prior experience of feeding at the alternative site chose the alternative, whereas fish with no prior experience chose the site at which their conspecifics had fed. Experiment 2 tested theoretical predictions that when the use of information acquired through personal experience is potentially costly, conflicting social information will be weighed more heavily than will personal information. The prediction was confirmed because, when given a choice between feeding at two food patches, one at which they had previously seen conspecifics feed and one behind a visual barrier, individual fish with prior experience of feeding behind the barrier chose the site at which their conspecifics had fed. These findings suggest that conformity can promote social learning in naïve individuals, but prior experience can insulate individuals from conformity provided the costs of relying on that experience are small. In addition, the experiments highlight the fact that personal and social information are not always weighed equally. Copyright 2004.