Dr. Babak Hemmatian is a cognitive scientist and postdoctoral research fellow at the Beckman Institute of the University of Illinois. His research focuses on using natural language processing techniques to analyze natural discourse, such as social media posts, as they relate to personal and political beliefs. In this episode we discuss Babak's background in computational cognitive science, his PhD research analyzing how Reddit and Twitter users' perspectives on the legalization of gay marriage and marijuana use changed over time, and the ethics of collecting data from social media users.