The Short Version
The underlying research supports a general link between cross-cutting social contact and reduced prejudice or affective polarization, but the claim overstates this by asserting that merely one differing-view close tie produces "significantly less extreme beliefs." Key studies actually measure prejudice or warmth toward out-groups—not belief extremity—and some research finds null or backfire effects depending on context and contact quality. The specific threshold framing and the word "significantly" go beyond what the evidence reliably demonstrates.