The external validity of MMPI-2 research conducted using college samples disproportionately represented by psychology majors

Psychology researchers have relied extensively on undergraduate college participants in their study of human behavior. Concern has been raised about the disproportionate representation of psychology majors among participants included in samples drawn from psychology department subject pools. In particular, MMPI researchers have relied extensively on college samples without reference to participant major. The present study compared the MMPI-2 profiles of 72 psychology majors with 425 college students specializing in other areas (e.g., social work, nursing, occupational therapy, physical therapy, criminal justice, communication disorders, biology, natural science, chemistry, chemical engineering, mechanical engineering, mathematics, and others). Psychology majors did not differ from comparison students on any of the MMPI-2 validity or clinical scales. Significant gender by college major interaction effects were not found. These profile symmetries provided assurance that efforts to control potential college major effects in published MMPI-2 research are unwarranted.