General practitioners predominate in osteopathic medicine (57% of all D.O.s), as compared with allopathic medicine. A number of possible reasons are put forth: the student selection process (cloning by admission committee general practitioners); special features of osteopathic education (more required courses, primary care courses, and rotations); training in osteopathic hospitals (mainly community institutions); a required rotating internship; and predominant departments of general practice in osteopathic hospitals and colleges (providing more high-quality general practitioner role models). The author suggests consideration of personality differences, as measured by the Myers-Briggs Type Indicator, as a possible causative factor in differences between the allopathic and osteopathic segments of medicine.