In psychological literature, Saul Rosenzweig (1936) coined this phrase the “Dodo bird verdict”, and it has been extensively referred to in subsequent literature as a consequence of the ‘common factor’ theory. This is the theory that the specific techniques that are applied in different types and schools of psychotherapy serve a very limited purpose (such as a shared myth to believe in), and that most of the positive effect that is gained from psychotherapy is due to factors that the schools have in common, namely the therapeutic effect of having a relationship with a therapist who is warm, respectful and friendly.
[…] The “Dodo bird verdict” is especially important because policymakers have to decide on the usefulness of investing in the diversity of psychotherapies that exist. The debate has been very much heated since its re-inception in 1975 with a publication of Lester Luborsky. Depending on what the outcome of the debate is held to be, many jobs and also the healthcare for many individuals are at stake.