Crazy as a Soup Sandwich - S3-E29
Other mistake: The actor playing Gus misses lifting a box to throw, and just makes a throwing motion with his empty arms.
Other mistake: Veteran actor Elisha Cook's name is misspelled "Elisa Cook" in the opening credits. (00:01:00)
Answer: They live in a totalitarian state where people who are deemed too smart (and therefore a threat to the authorities) are done away with. That's the point of the test, to eliminate potential troublemakers.
Brian Katcher