2. In Babcock et al.’s (2015) experiment on college students’ study room attendance, there are two types of reasons why students might be motivated to work harder in the “group incentives” treatment. One is a desire to avoid something negative, like a feeling of disapproval or unpleasant comments from a teammate; another is the “positive” opportunity to visit the room together and to help another student earn money and improve his or her grades. Why do the authors conclude that the “negative” motivations described previously were more important?