We report on the results of an experiment designed to disentangle behavioral biases in information aggregation of committees. Subjects get private signals about the state of world, send binary messages, and finally vote under either majority or unanimity rules. Committee decisions are...

Existing theoretical and experimental studies have established that unanimity is a poor decision rule for promoting information aggregation. Despite this, unanimity is frequently used in committees making decisions on behalf of society. This paper shows that when committee members are exposed to...