The Dodo bird verdict (or Dodo bird conjecture) is a controversial topic in psychotherapy, referring to the claim that all empirically validated psychotherapies, regardless of their specific components, produce equivalent outcomes. It is named after the Dodo character in Alice in Wonderland. The conjecture was introduced by Saul Rosenzweig in 1936, drawing on imagery from Lewis Carroll's novel Alice's Adventures in Wonderland, but only came into prominence with the emergence of new research evidence in the 1970s.
The importance of the continuing debate surrounding the Dodo bird verdict stems from its implications for professionals involved in the field of psychotherapy and the psychotherapies made available to clients.
The Dodo bird verdict terminology was coined by Saul Rosenzweig in 1936 to illustrate the notion that all therapies are equally effective. Rosenzweig borrowed the phrase from Lewis Carroll's 1865 book, Alice in Wonderland, wherein a number of characters become wet and, in order to dry themselves, the Dodo Bird 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 the case of psychotherapies, Rosenzweig argued that common factors were more important than specific technical differences, so that (on the Dodo bird conjecture) all therapies are winners; they all produce equally effective outcomes.