Passage Summary: Doris thinks joining student government makes kids more talkative. Zack thinks talkative kids are just the ones who join, and the activity itself doesn't actually change anyone's personality.

Reasoning: Doris claims student government involvement causes students to become outspoken, while Zack claims that outspokenness is the reason students join in the first place and that joining won't change them.

Analysis: The disagreement here centers on the direction of causality. Doris believes the activity (student government) causes the trait (outspokenness), whereas Zack believes the trait causes the activity and that the activity has no effect on the trait. When evaluating the options, use the 'Agree/Disagree' test: Doris would agree that student government makes people more outspoken, while Zack would explicitly disagree. The correct answer will highlight this specific clash over whether the involvement actually changes the students.