Let’s see we all know that everybody develops these preconceived notions about everything. They may be taught about it, but mostly they have experienced that notion overtime to make it a permanent part of their lives but when this notion develops into intolerance about somebody then it becomes dangerous. Then this notion and intolerance breeds into resistance to change or to new thoughts even when presented with evidence. It is human nature that resistance to new things is always strong. But to overcome those means that you have conquered your learned notions. You can see all around you and the preconceived notions just keeps on coming up. In the movies, television, and the general media and also individuals have made up in their mind that a certain race or ethnicity will act in a certain way and then that notion is hard to shed off.
Although there are laws which makes it punishable to discriminate on the basis of race, ethnicity and the like but unless it is ingrained from the start that all humans being are equal, the preconceived notions, intolerance of other people based on that notion and then to resist a thought which is totally opposite to what you have experienced or thought will never change. And this process of accepting other people and respecting their opinions and developing new thoughts is constant and goes on throughout your lives. It is like continuing education on your beliefs and attitudes and fine tuning you into a responsible citizen of the society.