When following the leader can lead into the jaws of death

International study of animal behaviour has important implications for human decision-making

Follow that fish -- threespine sticklebacks that were used in the experiments. Click here for more information.

For animals that live in social groups, and that includes humans, blindly following a leader could place them in danger.

To avoid this, animals have developed simple but effective behaviour to follow where at least a few of them dare to tread – rather than follow a single group member.

This pattern of behaviour reduces the risk of imitating maverick behaviour of an individual as the group recognise that consensus is better than following someone that goes it alone.

The study was carried out at the University of Leicester, by Ashley J. W. Ward now at the University of Sydney and in collaboration with David J. T. Sumpter of Uppsala University; Iain D. Couzin of Princeton University; Paul J. B. Hart of the University of Leicester and Jens Krause of the University of Leeds. It is published in the Proceedings of the National Academy of Sciences (PNAS). The research was funded by the Natural Environment Research Council.

Dr Ward, formerly of the University of Leicester, led the study. He said: “Social conformity and the desire to follow a leader, regardless of cost, exert extremely powerful influences on the behaviour of social animals, from fish to sheep to humans.

“The decision of whether to follow the lead of another individual is a fundamental problem for grouping animals - leadership in an animal social group may be assumed by an individual (or individuals) which exhibit a directional preference according to the habitat information it holds. This may be information about, for example, the location of food or a predator’s whereabouts. In such cases, the benefits to followers of acquiring this information may be significant, but whilst information is a valuable commodity, simple acceptance or ‘blind copying’ could result in a string of ill-informed decisions. Thus group members should exercise a degree of discrimination with regards to whom they follow.”

The team investigated how animals use the behaviour of others to make more accurate movement decisions, especially when it isn’t possible to identify which individuals possess pertinent information? One plausible answer is that animals in groups only respond when they see a threshold number of fellow group members perform a particular behaviour.