"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.
As a subplot, Jasper visits the Kwik-E-Mart and attempts to empty the freezer containing ice cream in order to freeze himself, with the intention of being defrosted sometime in the distant future. Apu decides to take advantage of this unusual situation for financial gain by advertising the frozen Jasper as "Frostillicus" and re-branding the Kwik-E-Mart as the Freak-E-Mart. The convenience store becomes a tourist trap and begins to generate a fair amount of money, until the freezer's cooling system fails, causing Jasper to defrost and walk away. Fearing that he will lose customers, Apu turns the Freak-E-Mart into a combination of a convenience store and a strip club and renames his store to Nude-E-Mart.
After watching Bart and Homer eat candy they had hidden in the sofa, Lisa imagines her future, which involves her being married to Ralph, being severely obese, and having many children. This frightens Lisa, causing her to appear on the TV news program Smartline to tell the citizens of Springfield to treasure their brains. As she does this, Homer decides to prove her wrong, and contacts the entire Simpson family to visit, so he can prove that some of the members of the family are intelligent. However, when they arrive, they are found to also be unsuccessful, unintelligent people, causing Homer to send them home. However, Marge reminds Homer that he did not talk to any of the women of the family. When he does, he discovers that the women are all successful: doctors, architects, lawyers, and a sales coordinator of a large company specializing in bunk and trundle beds. The females reveal that the defective "Simpson Gene" is only on the Y chromosome, meaning only the men are affected. The episode ends with Lisa finally being able to solve the brain teaser she was unable to finish earlier in the episode.
This episode was the final episode that was run by Bill Oakley and Josh Weinstein, as it was a carry over episode from season eight. The episode was written by Ned Goldreyer, and is one of the two episodes he has written on The Simpsons. The plot of the episode was similar to experiences that happened during Goldreyer's youth, where he was assumed to be a genius by some, but was really unintelligent. Susie Dietter, one of the directors of the show, also left the show after this episode, but returned for one episode in season 18, Yokel Chords.
As it was the final episode they ran, Oakley and Weinstein wanted to end on a good note, with Weinstein stating the episode, "was meant to embody the humor, depth, and emotions of The Simpsons." They also wished to have an episode they ran that was based on the background of every character they could do, and believed that this episode came out well. The name of the episode was the center of an argument that Oakley and Weinstein had, as Oakley had originally wanted to have the episode named "Lisa the Simpson", although Weinstein wanted to name it "Suddenly Stupid", a pun on a show that had been airing at the time called "Suddenly Susan".
The Simpsons family members that showed up took some time to be made, but the staff enjoyed the results. All of the male Simpsons family members that showed up were voiced by Dan Castellaneta, the voice of Homer. He had asked for the recording tape to be run for about 20 minutes, so he could do many different voice variations that would fit the different men, but still be close to Homer's voice.
Bill Oakley and Josh Weinstein greatly enjoyed the episode and thought of it as a great final episode that they ran. Oakley believes the episode to be, "The best episode ever produced, or at least written."