Frasier: IQ (1999)

Synopsis
This is the episode that answers the burning question: Which Crane brother is smarter, Frasier (Kelsey Grammer) or Niles (David Hyde Pierce)? The brothers' childhood IQ tests, long kept secret by their late mother, have finally been released, and the stats are in. Naturally, the results are more satisfying for one sibling than for the other -- and just as naturally, the behavior of both Frasier and Niles is more appropriate for petulant kiddies than responsible adults. ~ Hal Erickson, All Movie Guide