[Houshalter]

FWIW, there is a phenomenon called "Epistemic Learned Helplessness", that most people don't change their minds when given evidence, and this isn't necessarily irrational: http://squid314.livejournal.com/350090.html?thread=3855754

I mean your example is pretty extreme, I'm not going to say that was rational. But in general the average person doesn't have enough scientific knowledge to dispute a scientific study. In fact it's actually quite easy to make a case for almost anything by cherry picking studies.

So people have to rely on taking the consensus of others in their social group, or authorities they trust. And it means they don't actually have an opinion themselves, so you can't argue against them. They are just trusting the opinions of someone else.

This actually isn't a bad heuristic in general, but can lead to crazy beliefs like that. I think we all do this to some degree. I believe in global warming, but I couldn't possibly dispute any arguments against it that you could give me. I'm not going to change my mind though.