Are you too dumb to think?

I understand that it is hard to hear opinions that contradict yours.

I understand that it is difficult to compute the fact that despite ~5 billion religious believers in the world not a single one of them can produce factual evidence of their God’s existence at any other location than as a ghost in their minds. Furthermore, I understand that they get offended and angry when I question the ghost they hold precious.

I do understand that it is difficult for a Trump supporter to hear critical opinions on his/her malignant narcissistic liar of a presidential cunt.

I do understand that it is hard for the unhealthy overweight person to hear that s/he is a victim of a failing diet. A diet that for many is utilized as self medication of anxiety and other psychological issues.

But in either of these cases I do not understand when, or why, the intellectual process came to an end within them. I do not understand why these people stopped thinking.

Are these people intellectually lazy or are they just intellectually incapable – as in dumb? If the latter, is it possible to activate their capability of critical thinking? I’ve tried it repeatedly but have failed every time. Is it me or is it my subject who is too dumb to think straight?