TOEFL Reading: ETS-TOEFL阅读机经 - 433Q1RM33P0Z64K6L$

According to paragraph 6, which of the following has NOT been shown to decrease social loafing A. Participants know that fellow group members are willing, reliable, and competent. B. The group's task is seen as a challenge. C. Group members know and like each other. D. Participants know that their group is being judged on its performance.