 After a quarrel with Dr. Hibbert, Homer decides to enlist Maggie for a pre-nursery school. Maggie doesn t get tested because she can t talk. Back home Lisa discovers Maggie can make words and the family goes back to the pre-nursery school. This time Maggie passes the test gloriously and turns out to have an IQ of 167. This is more than Lisa s IQ (159) which makes her unsure about her identity.