2020 年 9 巻 1 号 p. 45-50
Prior researches on groupthink found out that group discussion is not always productive. The present study examined the effects of discussion on planning and performance. In study 1, 62 participants (31 dyads) answered questionnaire A, and the other 68 participants (34 dyads) answered questionnaire B. Participants answered Q1, then discussed with each other, and answered Q2. Study 2 was held one week later with 197 participants, including most of the participants of study 1. They took the term exam and answered the same questionnaire. Statistical analysis revealed that planned study hours for the exam became significantly longer after the discussion. It implies that discussion with other person boosts people's motivation to strive toward the goal. On the other hand, the test scores of discussed participants were not significantly different from those of non-discussed participants. The effect of discussion seems weak. Participants with a specific goal got better scores than participants with an abstract goal. Although there was not a significant difference, this outcome is consistent with the prediction of the goal-setting theory. Participants of the friend-dyad got better scores than participants of the stranger-dyad. However, the validity of this outcome is limited because the dyad formation was not strictly random.