Unfortunately, it's an age old dilemma and has been the cause of persecution, oppression, slavery, disputes and wars throughout the centuries. Even a younger America, with it's declaration that all men were created equal, allowed slavery and segregation to exist (until it finally came to its senses, for the most part). But pride and prejudice still continue and those that are viewed as inferior still suffer. I personally can't your question as to whypeople think they are better than others, but I can offer some Biblical support on the effects of pride:
Read Psalm 73, Proverbs 11:2, Proverbs 13:10, Proverbs 16:18, Proverbs 29:23, Isaiah 2:17, Psalm 10, 2 Chronicles 32
Some people were just blessed with great voices from God and others werent, that's what I think.
because some people think they are better than others normilly about race
"Arrogant" or "delusional" (if the person is NOT actually better than others). Keep in mind, some people ARE better than others (i.e. more talented/skillful/knowledgeable/etc). In those cases, they aren't 'arrogant' or "delusional" they are just 'better' than others.
Some people are better dancers than others because their coordination might be better.
That is a matter of ones own opinion. Some people may think Chris Johnson is better. While others may think Adrian Peterson is better.
they need to make others feel bad in order to think better of themselves.
There are both great countries. Some aspects of each are better than the other.
Hinduism does not believe that some people are better than others but focuses on members of the religion being the best that they can be.
This question really depends on the idea of each person. Some people think that British Columbia have had good healthcare for single mothers, but some others think that It is.
It is a matter of opinion. Some think M. Shadows is better, while others think that Synyster Gates is better.
If some Jews think they are 'better than others' it is no different from some Christians and Muslims who think that morally and spiritually they tower above head and shoulders above ordinary people. In my experience they Jews don't 'bang on' about the subject, though. Perhaps the notion that Jews think they are better is part of the stereotype?
some people think meat is best and some people think vegetables are better