Echo-chambers as distinguished from epistemic bubbles. With its insistence on evidence, citations etc. around some topics and on some sub-forums, MN is neither despite moderation and external interference influence. It's vanishingly rare for people with some perspectives to bring data and citations that are accurate to a discussion about evidence.
Something has gone wrong with the flow of information. It’s not just that different people are drawing subtly different conclusions from the same evidence. It seems like different intellectual communities no longer share basic foundational beliefs. Maybe nobody cares about the truth anymore, as some have started to worry. Maybe political allegiance has replaced basic reasoning skills. Maybe we’ve all become trapped in echo chambers of our own making – wrapping ourselves in an intellectually impenetrable layer of likeminded friends and web pages and social media feeds.
But 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.
Current usage has blurred this crucial distinction, so let me introduce a somewhat artificial taxonomy. An ‘epistemic bubble’ is an informational network from which relevant voices have been excluded by omission. That omission might be purposeful: we might be selectively avoiding contact with contrary views because, say, they make us uncomfortable…
An ‘echo chamber’ is a social structure from which other relevant voices have been actively discredited. Where an epistemic bubble merely omits contrary views, an echo chamber brings its members to actively distrust outsiders.
[People in an echo chamber are alienated from outside sources. Outside is labelled as malignant and untrustworthy. So, for people like Limbaugh follower under discussion] exposure to contrary views could actually reinforce their views. Limbaugh might offer his followers a conspiracy theory: anybody who criticises him is doing it at the behest of a secret cabal of evil elites, which has already seized control of the mainstream media. His followers are now protected against simple exposure to contrary evidence. In fact, the more they find that the mainstream media calls out Limbaugh for inaccuracy, the more Limbaugh’s predictions will be confirmed. Perversely, exposure to outsiders with contrary views can thus increase echo-chamber members’ confidence in their insider sources, and hence their attachment to their worldview. The philosopher Endre Begby calls this effect ‘evidential pre-emption’. What’s happening is a kind of intellectual judo, in which the power and enthusiasm of contrary voices are turned against those contrary voices through a carefully rigged internal structure of belief.
https://aeon.co/essays/why-its-as-hard-to-escape-an-echo-chamber-as-it-is-to-flee-a-cult
Begby, Endre, 'Evidential Preemption', Prejudice: A Study in Non-Ideal Epistemology (Oxford, 2021; online edn, Oxford Academic, 18 Mar. 2021), https://doi.org/10.1093/oso/9780198852834.003.0007