The Dynamic Decision-Making of Ants

Takao Sasaki and Stephen Pratt at Arizona State University reported this week in Biology Letters that ants making decisions can continuously update their strategy or rules based past experience. The colony of Temnothorax rugatulus ants were confronted with a choice between two nests, differing in either size or light intensity. In the wild, this species resides in fragile rock crevices and is frequently forced to find a new nest. As in human decision making processes, the choice of nest is contingent upon several qualities and it is unlikely that any habitat will be superior across all the criteria. As a result, the importance of the qualities must be weighted.

The paradigms performed by this group demonstrated for the first time that this order or queue of the attributes was dynamic and based on prior experience. The initial choice allowed the ants to choose between options varying on only one attribute. This was followed by a choice where the options varied in two dimensions but the ants had learned to increase the weight of attribute already presented relative to the second parameter. The authors believe this change in the weighting of the different dimensions is because ,in the initial ‘training’ choice, only one dimension was informative. This ability to re-prioritize is often considered to be a sign of intelligence and in multiple-attribute decisions had hitherto not been seen in such a species.

What is interesting about ant decisions, as compared to humans’, is that they reach consensus as a single unit, with little dissent. The global aim of the group’s research is to understand the relationship between the individual’s decision and that of the colony, with the overarching aim of using understanding of this collective decision-making to provide information on how people, as part of society, can reach consensus.

Read more at: http://asunews.asu.edu/20131106-ants-decision-making