Lecture by ICE Fellow Daniel Singer

Wilder Hall, Room 115, Dartmouth College
It is common, especially among psychologists, to see polarization as the product of human irrationality when it occurs in response to shared evidence and arguments. In contrast, I'll show that the persistent disagreement that grounds political and social polarization can be produced by rational agents. I'll use agent-based computer models of group deliberation to show that groups of agents using a rational coherence-based strategy for managing their limited cognitive resources tend to polarize, even when they are sharing their evidence and arguments. I'll then show that how and what we forget has a profound effect on whether groups can achieve optimal epistemic outcomes, and in some cases, the effect outweighs how group members share their information. This result undermines the popular idea that we should be focusing how members of groups contribute (by encouraging folks to speak up when they have something to add, for example) and instead suggests that we should focus more attention on helping people regulate their own memory and internal information processing.