Researchers conduct a study in which university students are asked to solve puzzles, a task that all students in the experiment report enjoying before the study. They split the students into two groups: a group that is paid money for doing the puzzles, and a group that is not. The researchers then observe how often students in each group complete puzzles during their break time when they are allowed to do whatever they want. Assuming that their results are consistent with previous findings, the researchers are most likely to find that