I'm tempted to call it a dogma, but it strikes me as something much more visceral than that. The closest that comes to mind is a mulish rejection of reason when it strikes emotionally rooted beliefs. Calling it "Anti-science" is valid but tricky, because the anti-scientific part can be very selective: argue with certain people about the safety of vaccine science and they reject you outright no matter what evidence you offer, but explain how a cell phone works to these same people and they'll happily defer to scientific explanations.

maybe "memes" are a useful term?

seems some memes get stuck in peoples heads and blocks all reasonable discussions?