The Influence of Social Rank on Learning in a Cichlid Fish

Abstract

Learning allows animals to adapt to new and changing environments. Animals can learn through their own personal experiences, known as asocial or individual learning. Asocial learning produces reliable information, but it can be energetically costly and risky for the learner. So instead of learning on their own, animals can choose to learn by observing and copying the behaviours and choices of others, known as social learning. However, because individuals that socially learn are gaining second-hand information, this form of learning is often less reliable. Animals are expected to be flexible in their use of individual versus social information, and to use whatever strategy provides the greatest benefits. Not all animals or individuals have been found to employ a flexible strategy, and research shows that many have a clear preference for one type of learning over the other. This preference for social or individual learning can be influenced by their personality, their sex and even an individual’s reproductive status. Another factor that could influence learning is an individual’s rank, but this topic has received little attention. In my M.SC. research, I studied how social rank influences an individual’s performance in an asocial and in a social learning task using the cichlid fish Neolamprologus pulcher. Using this species I also tested if social rank influences information use, by providing conflicting individual and social information to the fish. I found that subordinate N. pulcher were faster at a reversal learning (suppressing a previously learned rule and learning a new one), but there were no clear differences between the social ranks in associative learning or in social learning. When presented with conflicting individual and social information, both subordinate and dominant N. pulcher relied on individual information first. However, dominant N. pulcher were more likely to also use the conflicting social information in addition to their individual information. Taken together these results help us better understand cognitive differences between social ranks, and shed light on how information and behaviours in social groups can be learned and spread.