Group expertise: The effect of experience on collective decision-making

Background/Question/Methods

Expertise allows individuals to perform significantly better than novices on a complex task. Social groups can also develop expertise from extensive collective experience. Within group expertise, collective decision-making is crucial for maintaining cohesion, but it is unknown whether a group’s collective decision-making skills can improve with experience. To investigate this, we tested whether repeated experience choosing between two nests during emigration in acorn ants (Temnothorax ambiguus) would improve the speed and efficiency with which colonies reach consensus. We predicted that experience with collective decisions improves colony decision-making efficiency and speed. We first ran preliminary experiments to quantify nest features that colonies prefer in order to establish good-quality and mediocre-quality artificial nests. Twenty colonies belonging to the choice treatment emigrated six times with a choice between a good- and mediocre-quality nest. Another 20 colonies belonging to the no-choice treatment emigrated six times with no choice, as they were provided with a single nest. Then, we tested both treatments with the choice between a good- and mediocre-quality nest during a final emigration.

Results/Conclusions

We found that colonies with experience on a binary decision-making task were more efficient, but not faster, at reaching consensus than colonies without binary experience in decision-making. Additionally, we found that decision-making speed did not differ when choosing between two nests compared to one. We conclude that previous experience making decisions can improve subsequent decision-making. Studying decision-making in ants will allow us to achieve an improved understanding of the development and mechanisms behind group expertise.