Pride and Shame

Many people seem to take pride in the circumstances of their birth, which they had absolutely no control over.  How can anyone have pride or shame in things they had no involvement in creating or accomplishing?   It's a question I pose often to those with pride for their nation of origin, skin color, and sexual orientation.  Usually this question is answered not with a reasonable response, but attacks and hostility.  

Perhaps pride in such things must be valid in their minds because they have no accomplishments of their own to take pride in.  I believe my question triggers cognitive dissonance and defense mechanisms that cause them to lash out at me.  All I did was question the source of their pride, a valid way to understand why they have pride in arbitrary circumstances of birth.  

Maybe someone with this pride I have no understanding of can explain it to me in the comments, I'm always ready to learn why people think the way they do.  From my point of view, pride should be for accomplishments, and shame should be for failures.  Utilizing pride and shame for anything else is just silly to me, and causes divisions in our society for the most ridiculous reasons.  

My best guess is primal tribalism is still a big part of the human psyche, even if we've never had a need for it in our own lives.  Back when we were living in caves, fear of people that didn't look the same as us was likely life saving.  Those people were probably part of a rival tribe that competed for territory and resources, as many animals still do today.  The imperative of self-preservation would require us to be suspicious of outsiders.  So, much like the inherent instinct to consume too much food even when there is no danger of starvation, tribalism and racism is an instinct we all must overcome, and some of us will inevitably fail to do so.