Happily putting the pieces together: a test of two explanations for the effects of mood on group-level information processing.

Research on mood and information processing reveals two explanations for how moods might influence decision-making in a group. Moods may alter group decision making because happy moods are more likely than sad moods to (a) increase people's reliance on accessible knowledge or (b) broaden people's focus so they can build on their knowledge. Consistent with the hypothesis that happy moods broaden-and-build on people's knowledge, across two experiments, happy moods promoted group performance more than sad moods because happy moods helped group members move beyond their initial preferences and focus broadly on the full range of information that each group member could provide. Experiment 2 built on these findings by demonstrating that the effects of mood on group performance were particularly strong when the critical information was uniquely, rather than commonly, distributed to group members. These experiments clarify the role of mood in group decision making and suggest that a differential focus on unique/critical information relative to common/non-critical information may be a key mechanism in understanding the effects of mood on group decision making.