When we affirm each other’s “right” to believe things—even things that fly in the face of evidence—we essentially decouple critical thinking and belief revision. This damages the norm that keeps minds tethered to reality. A Canadian research team recently made an important discovery: when people lose the “meta-belief” that beliefs should change in response to evidence, they become more susceptible to conspiracy theories, paranormal beliefs, science denial and extremism—mind viruses, if you will. This is a critical finding. I like to put it more simply: the idea that beliefs should yield to evidence is the linchpin of the mind’s immune system: remove it—or even chip away at it—and an Internet-connected mind will eventually be overrun by mind parasites. When this happens to enough minds, all hell breaks loose.
This is the root cause of our post-truth predicament. When we buy into the prevailing fundamentalism about speech rights, or downplay the importance of accountable talk, we exacerbate an increasingly existential problem.
The deep culprit here is not a shadowy government insider. It’s not an aspiring demagogue or a corrupt political party. Trace the problem to its roots and you find a compromised cultural immune system. Astonishingly irrational ideas proliferate because they’re playing us.
If we continue to let them play us, we’ll chase each other down the rabbit hole of delusion. There’s really only one alternative. First, we must grasp that bad ideas are mind-parasites—entities that can proliferate and harm the very minds that host them. In fact, they can lay waste to delusion-tolerant cultures. Second, it’s time to take the emerging science of mental immunity seriously. We must grasp how mental immune systems work, and work out how to strengthen them. Then, we need to inoculate one another against the worst forms of cognitive contagion.