“There are two very different phenomena at play here, each of which subvert the flow of information in very distinct ways. Let’s call them echo chambers and epistemic bubbles. Both are social structures that systematically exclude sources of information. Both exaggerate their members’ confidence in their beliefs. But they work in entirely different ways, and they require very different modes of intervention. An epistemic bubble is when you don’t hear people from the other side. An echo chamber is what happens when you don’t trust people from the other side.”