7. Taking A Test
In an episode that has already been referred to in this article - "Petarded" - Peter does something unfathomably dumb. After winning a game of Trivial Pursuit against his family members (for the simple reason that Lois uses questions from the preschool edition for Peter in order to let him win), Peter declares himself a genius. Questioning this obviously incorrect declaration, Brian persuades Peter to prove it by urging him to take the MacArthur Fellows Program test. Instead of using a calculator in the exam, Peter opts to use a See 'n' Say toy which simply makes animal noises. Every time Peter presses a button, the toy makes a "moo" or a "woof" sound and Peter, thinking it is giving him the answer to the questions, says "ah of course" and writes those noises down as his answers. As a result, he is officially declared mentally retarded.