Psychopathological interpretations of individuals who claim contacts with extraterrestrials typify the few psychiatric evaluations of such behavior. Biographical analyses of 152 subjects who reported temporary abductions or persistent contacts with UFO occupants show that these subjects are remarkably devoid of a history of mental illness. However, in 132 cases, one or more major characteristics were found of what Wilson and Barber (1981) identified as the fantasy-prone personality (FPP). Although they appear to function as normal, healthy adults, FPPs experience rich fantasy lives and score dramatically higher (relative to control groups) on such characteristics as hypnotic susceptibility, psychic ability, healing, out-of-body experiences, automatic writing, religious visions, and apparitional experiences. In the present study, UFO "abductees" and "contactees" exhibit a pattern of symptomatology similar to that of FPPs. Thus, clinicians should consider testing UFO abductees or contactees for fantasy proneness in cases in which a particular psychopathological diagnosis is not obvious.With the centennial of The Principles of Psychology (James, 1890), the work that earned William James the title of founder of scientific psychology in America (Boring, 1929), it might be profitable to reconsider one of his most basic philosophical principles: the pragmatic view of truth and reality. The notion appeared in embryonic form in these words:In the relative sense, then, the sense in which we contrast reality with simple unreality, and in which one thing is said to have more reality than another, and to be more believed, reality means simply relation to our emotional and active life. This is the only sense which the word ever has in the mouths of practical men. In this sense, whatever excites and stimulates our interest is real; whenever an object so appeals to us that we turn to it, accept it, fill our mind with it, or practically take account of it, so far it is real for us, and we believe it. Whenever, on the contrary, we ignore it, fail to consider it or act upon it, despise it, reject it, forget it, so far it is unreal for us and disbelieved. (James, 1890, p. 924) In a little less than two decades, James had refined this perspective into the instrumental (or pragmatic) view of reality and truth: