Juvenile cleaner fish can socially learn the consequences of cheating

Noa Truskanov,Yasmin Emery,Redouan Bshary

doi:10.1038/s41467-020-14712-3

Abstract

Social learning is often proposed as an important driver of the evolution of human cooperation. In this view, cooperation in other species might be restricted because it mostly relies on individually learned or innate behaviours. Here, we show that juvenile cleaner fish (Labroides dimidiatus) can learn socially about cheating consequences in an experimental paradigm that mimics cleaners’ cooperative interactions with client fish. Juvenile cleaners that had observed adults interacting with model clients learned to (1) behave more cooperatively after observing clients fleeing in response to cheating; (2) prefer clients that were tolerant to cheating; but (3) did not copy adults’ arbitrary feeding preferences. These results confirm that social learning can play an active role in the development of cooperative strategies in a non-human animal. They further show that negative responses to cheating can potentially shape the reputation of cheated individuals, influencing cooperation dynamics in interaction networks.

Highlights

Social learning is often proposed as an important driver of the evolution of human cooperation
The design allowed subjects to combine the social information with personal experience obtained during the tests, a situation that is likely to resemble juvenile cleaners’ opportunities for social learning under natural conditions
Our results show the ability of a non-human animal to learn socially about behavioural strategies in an experimental paradigm that mimics cooperating/cheating in interspecific social interactions

Summary

Introduction

Social learning is often proposed as an important driver of the evolution of human cooperation. Juvenile cleaners that had observed adults interacting with model clients learned to (1) behave more cooperatively after observing clients fleeing in response to cheating; (2) prefer clients that were tolerant to cheating; but (3) did not copy adults’ arbitrary feeding preferences These results confirm that social learning can play an active role in the development of cooperative strategies in a non-human animal. Given that cleaners interact with a range of clients that differ in abundance, parasite load, mucus quality and responsiveness to cheating[32,33,34], observing conspecifics interact with clients may provide cleaners with useful information about when and with whom to cooperate Such information may be especially relevant to young cleaners, who tend to spatially overlap with adults, but may have had less opportunities to gain relevant personal experience as their client assembly shifts along their ontogeny[35,36]

Methods

Results

Conclusion