Final answer:
The behavior described in the scenario where control group members arrange their own review sessions to compete with the experimental group is known as compensatory rivalry, which can bias the results of a study.
Step-by-step explanation:
In the described experiment to test the effectiveness of review sessions on exam grades, you identified that you were part of the control group because you did not receive any additional review sessions and only took the scheduled exams. However, upon realizing this, you organized a review session with other control group subjects in order to avoid being outperformed by the experimental group. This behavior illustrates compensatory rivalry, which refers to the situation where control group members, aware of their control status, take steps to compensate for the lack of experimental treatment, potentially skewing the study's outcomes.