Answer:
In chapter 4, Jem imposes gender roles on Scout twice. The first is when the tire they've been playing with rolls into the Radley's yard. Jem, Dill, and Scout are all terrified to go into the yard to retrieve it, and after some hesitation, Jem dashes in to get it. Instead of admitting his fear, he turns on Scout and says "I swear, Scout, sometimes you act so much like a girl it's mortifyin'." Right after that episode, Jem invents a game in which they'll emulate the Radley family, and he assigns Scout the role of Mrs. Radley even though she objects; moreover, the only action she gets to complete is sweeping the porch. In subsequent games, she "reluctantly played assorted ladies who entered the script." At the end of the chapter, Jem once again denounces Scout for her caution, saying that she was being a girl, that girls always imagined things, that's why other people hated them so, and if I started behaving like one I could just go off and find some to play with.