Story Staying Power

I read this article, Multiculturalism, Chronic Illness, and Disability, about the stories different cultures tell about chronic illness and disability. Sadly, much is based on superstitions, folklore and religious beliefs. It was overwhelmingly negative. One is disabled because of a family curse, another is he or she did something bad in a past life, and one more is being disabled is a form of "punishment." I got the impression that these stories are deep seated and are almost impossible to re-write or let go of all together. I think this applies to many of our stereo-types that simply do not hold up to any serious scrutiny. Why do they persist?

My default when answering such a question is asking who benefits? If disabled people are denied access to jobs and social interactions, that means less competition for non-disabled people. If African Americans are treated in the same manner, European Americans benefit, right? Is this an over simplification?  What I'm getting at is the persistent stories that many believe, even when they are untrue.My question to you guys is what makes some myths stick around much longer than they should? 

-Paul