The germ theory myth and the myth of outcome homogeneity

In efforts to respond to Kiesler's (1966) concerns with the myths of therapist, patient, and therapy uniformity, researchers have manualized psychotherapies and worked with increasingly homogeneous patient groups. Thus, instead of seeking to understand the sources of variability that contribute to outcome, they have tried to eliminate it. In this process they have not only made the psychotherapy studied in research less and less similar to that which takes place in practice, but they have introduced other myths to Kiesler's list, as well. For example, researchers and practitioners alike continue to operate on the ''Germ Theory'' myth of education-They assume that exposure to psychotherapy principles over a specified and finite period of time results in expertise. Moreover, they have continued to accept the ''Myth of Therapy Outcome Uniformity''-the belief that all psychotherapies evoke similar outcomes. These two myths are explored and evidence is presented to indicate that both may hamper the development of sound research programs.