On a serious note, science of the brain has exploded in last decade .
The human brain above all seeks to maintain a balance, having to change your mind about long held views/ knowledge can upset that balance which
can cause health problems, mental and physical . that can even result in
death .
Ever seen a hard-core racist change his mind through rational discourse ?
Neither has anyone else .
The brain is fully capable of and often does , make someone who learned and firmly believes that something can not make a difference UNABLE to hear,see or grasp that difference should it exist , if it knows balance will be upset .
It cares nothing about science.
People are not usually being bull-headed just to be same, most often
they are just following orders from headquarters .