Discrimination: A self-fulfilling prophecy

I had an early lunch today, eating outside a Chinese restaurant on the Loop. When we were nearly finished eating, a pair of city workers walked up to the restaurant and were greeted by the hostess, who asked in a thick accent if they wanted lunch ''for here or to go." One worker instantly got mad, apparently not hearing the "for here or" part, and loudly proclaimed that they hadn't even gotten inside before they were asked to go! He just assumed they weren't welcome and decided to find somewhere else to eat.

The way I saw the situation, he went into the incident with a mental set that he would be the target of discrimination. Then, when there was an ambiguous interaction, he took it in a way that fit his expectation, and reacted in away that was certainly not warranted.

When people expect to be trodden upon, then they do get trodden upon or at least feel that they are. This vicious cycle breeds nothing but hatred, indignation, and misunderstanding. But how do we, as a society, break the cycle, especially when it seems that so many people choose to live and act by bitter misperception?