Thomas Costello is a postdoctoral fellow at the Massachusetts Institute of Technology Sloan School of Management. He studies the psychology of politics, focusing on ideology, authoritarianism and radicalism.

Written by Thomas Costello

Photo of a bearded man holding a US flag at an outdoor gathering, with blurred people and flags in the background.

Popper was right about the link between certainty and extremism

In terms of irrational confidence, many people at opposite ends of the political spectrum seem to have something in common

by Thomas Costello & Shauna Bowes