It’s one of the most common refrains in political discourse today: social media is the source of polarization. It’s a difficult proposition to empirically study because companies like Meta and X don’t share their data publicly. Until now.In a landmark series of papers, three in Science and one in Nature, Princeton political scientists Andy Guess and a massive team of researchers were given unique access by Meta to study how the platform and algorithms affected users’ attitudes and behaviors during the 2020 election. The findings are surprising and fascinating, even as the project itself raises intriguing questions about how to conduct research on a company in partnership with that very same company.