YAVIS (sometimes "YAVIS Syndrome") is an acronym based on the words "Young, Attractive, Verbal, Intelligent, and Successful"; it was coined by University of Minnesota professor William Schofield in his 1964 book "Psychotherapy: The Purchase of Friendship" in which he claimed to have demonstrated that mental health professionals often have a positive bias towards clients exhibiting these traits; such a bias in turn may predispose the professional to work harder to help such clients. Such a predisposition, although often or even mostly unconscious, was thought to be driven by an expectation that clients with such traits would be motivated to work harder in therapy, thereby increasing the therapist's hope that the treatment would effect a successful outcome (and thereby, in part, enhance the therapist's experience of him/herself as effective in their job).