Stu is in charge of hiring new employees for his office. In response to federal legislation, he is required to watch a video and attend a seminar on avoiding racial biases in hiring. Paranoid about his own potential racial biases, Stu tries very hard to consciously crush any stereotype that comes to mind when reviewing applicants. However, after several applicants, Stu suffers from a rebound due to the effortful nature of his cognitions, and actually begins to stereotype more. What is this an example of