There's a very specific mindset which makes people prone to believing conspiracy nonsense, new-age woo, and other such things, and I can't quite articulate what it is.
It's not necessarily directly related to intelligence; don't forget Steve Jobs was at least reasonably clever & very highly educated, and he tried to treat cancer with seaweed smoothies and meditation or whatever. I think maybe 'scientifically incurious', maybe?
It makes people mistrust any official sources of information, while almost unthinkingly swallow anything spouted off by any source which claims to be 'outside the mainstream'.
Whatever the specifics, it's the modern equivalent of being a cave-man with a gimpy leg, or a medieval peasant with a dodgy immune system, or a nineteenth-century industrial worker with poor situational awareness: You're going to starve to death / die of plague / get caught up in some whirling piece of machinery & torn to shreds / end up putting your faith in complete nonsense which, at best, will severely reduce your ability to compete in the modern world, or at worst will kill you when you try to fight a fully treatable illness with holistic vegan tantric crystals instead of actual, not pretend, medicine. Not to mention the very real possibility of getting held up by your ankles and shaken untill your gold fillings fall out by every con-man going.
It's the latest Darwinian pressure to be applied to the human race.