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The Dodo bird verdict is a phrase sometimes used when evaluating different techniques used in psychotherapy.

Psychological Significance

File:Dodo from Alice's Adventures in Wonderland.gif

"Everybody has won and all must have prizes."

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 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. Meta-analyses by Luborsky (2002) show that the effect size that can be attributed to specific therapy techniques is only 0.2. Therefore, all therapies are considered equal and "all must have prizes".


On the other hand, scientists who believe in empirically supported therapies (EST) contend that it is not a fair picture of affairs. Amongst many others Chambless (2002), for example, support the EST movement because there is much evidence that specific therapies are helpful to "specific people in specific situations with specific problems". The significance of the figure of 0.2 is then an artifact of grouping problems and therapies in a non-meaningful way. Chambless would say that the Dodo is extinct, and that it will always be.

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.

See also


  • Rosenzweig, Saul (1936). Some implicit common factors in diverse methods of psychotherapy. American Journal of Orthopsychiatry 6: 412-415.
  • Luborsky, Rosenthal, SIguer, Andrusyna, Berman, Levitt, Seligman, Krause (2002). The Dodo bird verdict is alive and well - mostly. Clinical Psychology: Science and Practice 9: 2-12.
  • Chambless, Dianne (2002). (commentaries) Beware the Dodo Bird: the dangers of overgeneralization. Clinical Psychology: Science and Practice 9: 13-16.

Further reading