Why do people cling to their beliefs despite overwhelming evidence to the contrary? Read The Science of Why We Don’t Believe Science.
It’s just that we have other important goals besides accuracy—including identity affirmation and protecting one’s sense of self—and often those make us highly resistant to changing our beliefs when the facts say we should.
I like Jason Snell’s way of describing science.
Science is, in many ways, a struggle to overcome our own personal biases and allow the truth to shine through.