"Lisa the Simpson" is the seventeenth episode of the ninth season of the animated television series The Simpsons, which originally aired March 8, 1998. It was written by Ned Goldreyer and directed by Susie Dietter. This episode was also the final episode with Bill Oakley and Josh Weinstein as show runners. The episode sees Lisa discovering a gene that runs in the family which makes the members unintelligent as they grow older.