The Dodo Bird Verdict
In Lewis Carroll’s Alice’s Adventures in Wonderland (1865), at a certain point a number of characters become wet. In order to dry themselves, the Dodo decided to issue a competition. Everyone was to run around the lake until they were dry. Nobody cared to measure how far each person had run, nor how long. When they asked the Dodo who had won, he thought long and hard and then said “Everybody has won and all must have prizes.”
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 factors 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.
Meta-analyses by Lester Luborsky (2002) show that the effect size that can be attributed to specific therapy techniques is only 0.2. In other words, the therapeutic orientation doesn’t matter because all orientations work. The single factor that makes a difference in outcome is faith: the patient must believe in the therapist, and the therapist must believe in his orientation and both parties must have faith, sometimes against all reason, that their expedition will succeed. Therefore, all therapies are considered equal and “all must have prizes”.
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.