The obvious parallel is the old story about hot water freezing faster than cold water [1]. An experimental character who notices this and gets laughed down by the vast and overwhelming majority of people who who only agree with consensus facts could logically end up in a /weird/ mental space.
They'd basically discover that they are surrounded by people who don't assess the facts directly, but do so through a lens of other people's opinions. It wouldn't take much to push them into conspiracy theories - clearly no-one around them is dealing directly with reality. Any who didn't take to conspiracies would probably be grounded enough to drive real change in the world.