Persistence of brainstorming groups: How do people know when to stop?

Two experiments compared task persistence and productivity for brainstormin g individuals and groups of various sizes under conditions without a time l imit. We expected that the stop rules people employ in deciding to end a se ssion would have important consequences for the relation between group size , persistence, and productivity. In Experiment I, conducted with individual s, dyads, and four- and six-person groups, it was found that persistence in creased linearly with group size. As a result, the productivity loss usual in brainstorming groups was substantially reduced. This finding was replica ted in Experiment 2, but only under conditions without time pressure. The d egree to which a brainstorming topic was perceived as enjoyable did not aff ect persistence. Findings were consistent with the hypothesis that people s top neither when they are satisfied with their performance nor when they no longer enjoy the task, but when the expected relation between effort and p erformance falls below a certain cut-off point. The theoretical and practic al implications of these findings are discussed. (C) 1999 Academic Press.