Philosophical anthropology is concerned with assumptions about human nature, differential psychology with the empirical investigation of such belief systems. A questionnaire composed of 64 questions concerning brain and consciousness, free will, evolution, meaning of life, belief in God, and theodicy problem was used to gather data from 563 students of psychology at seven universities and from 233 students enrolled in philosophy or the natural sciences.
Essential concepts were monism–dualism–complementarity, atheism–agnosticism–deism–theism, attitude toward transcendence–immanence, and self-ratings of religiosity and interest in meaning of life. The response profiles (Menschenbild) of women and men, and of psychology students in the first and midterm of study were very similar. The method of statistical twins indicated a number of differences between students of psychology, philosophy, and the natural sciences. The majority of respondents were convinced that philosophical preconceptions on mind–body and free will have important practical implications for the way in which psychotherapists, physicians, or and judges exercise their professions.