On this episode of the Argument Ninja podcast I talk about the difficulty of judging how much we really understand about the causes of complex social phenomena—even if we do lots of research and self-study. To help make the case I’m continuing my survey of different theories of the causes of the increase in social polarization that we’re currently experiencing. On this episode I look specifically at the work of two social scientists who have written extensively on this topic: Karen Stenner and Eric Kauffman.