ResearchBlogging.orgIndividual animals that live and and forage in groups may not always benefit from a particular move (to or from a foraging site) in the same way as other individuals in the group. Therefore, there must be some kind of negotiation among the critters. Theoretical work almost always seem to show that consensus based group decisions will prevail because this minimizes individual costs. The altnernative, despotic decision (where a dominant individual decides where the group goes) should rarely happen. But the theory is apparently weak because despotic decision making seems to occur in nature.

A study just out in Current Biology looks at democratic vs. despotic decision making in a free ranging broup of Baboons in Namibia (Tsaobis Leopard Park). Each group of baboons was given a chance to forage from an experimental food patch wihtihn its core home range. There were two kinds of artificial patches. Both patches allowed only a minority of individuals access, but one had significantly more competitive demand than the other. In this way, the dominant baboon would always get to feed, but some (in some cases more than other) of the other baboons would be likely excluded. The patches were available to the baboons for nearly three weeks each.

… The results show that group foraging decisions were consistently led by the individual who acquired the greatest benefits from those decisions, namely the dominant male. Subordinate group members followed the leader despite considerable consensus costs. Follower behavior was mediated by social ties to the leader, and where these ties were weaker, group fission was more likely to occur. Our findings highlight the importance of leader incentives and social relationships in group decision-making processes and the emergence of despotism.

… Our field experiments on wild baboons indicate that despotic group decisions can emerge when an individual has both a strong incentive to lead and sufficient social influence to elicit follower behavior. Follower behavior occurred despite consensus costs, but where social ties were weaker, group fission was more likely. The influential role of the leader was further highlighted by the observation that groups failed to visit the food patch when the leader’s priorities changed. Our findings emphasize the importance of leader incentives and social relationships in group decision-making processes and the emergence of despotism.

A KING, C DOUGLAS, E HUCHARD, N ISAAC, G COWLISHAW (2008). Dominance and Affiliation Mediate Despotism in a Social Primate Current Biology DOI: 10.1016/j.cub.2008.10.048