Van Goozen et al.'s (1997) study on the menstrual cycle had several limitations that reduced its mundane realism. Participants were studied for only one cycle, which limits continuity and generalizability. Additionally, subjects chose periods with no special life events (e.g., exams, weddings) and refrained from drinking and late bedtimes. The sample was restricted to individuals in stable, single-partner relationships who did not use oral contraceptives and lacked severe premenstrual symptoms. By controlling and removing so many typical daily-life factors, the experiment failed to capture a realistic picture of how bodies operate under normal conditions.