In the 1939 film, the Wizard gives the Scarecrow a diploma as a symbol of a brain.
The Scarecrow begins the story convinced that he is unintelligent because he is made of straw and believes he lacks a brain. Yet he repeatedly demonstrates practical judgment and creative problem-solving while traveling along the Yellow Brick Road. His wish to receive a brain is therefore treated as a question of confidence as much as intelligence.
When the travelers reach the Emerald City, the Wizard gives the Scarecrow an honorary diploma rather than a literal brain. The document serves as a public symbol that the Scarecrow already possesses the qualities he wants. Immediately afterward, the Scarecrow confidently recites a version of the Pythagorean theorem, although his wording is comically incorrect.
The other gifts follow the same symbolic pattern. The Tin Woodman receives a heart-shaped testimonial, while the Cowardly Lion receives a medal for courage. These objects do not magically transform the travelers; they recognize qualities they have shown throughout their journey. The diploma scene is one of the film’s clearest jokes about credentials and self-belief.