A talk with Emily Kubin, who recently, with her co-researcher Christian Von Sikorski, did a comprehensive review of 121 studies on social media effects on political polarization. We talk about her research, why polarization is a problem, the different types of polarization (affective vs ideological), our psychology tendency to become us-versus-them in our thinking, her own opinions on what social media is doing to us, and the mechanisms by which social media may be amplifying polarization.