Yes, people of different social classes interact well, because Americans are for the most part extremely generous. Most rich people are eager to provide charity and, if they own a business, jobs to those who are less fortunate than they are. The vast majority of the poor and middle class do not resent those who are not.
I think in general people of different social classes interact just fine. Usually you can not even tell the difference between a poor person and a more well of person. I have had friends dressed nicer than I was but be of a lower class. It just depends on how well you click.
Once we strip down the veneer that is social construct, people begin to just be people. You could put a homeless person in the same room as a million dollar athlete and they could still get along fine. Class is an economic barrier, not a human one. So I think people interact fine.
Yes, people of different social classes interact well, because for the most part, people understand that they are all people who are part of the human race. Some people do not work well together, but they are outliers. Most of the time, the wealthy genuinely want to help the poor, and the poor are genuinely friendly to those who have more.
Social class is not the sole determinate in whether or not people are able to act well. Commonalities, such as school or work or similar interests and compatibility play important roles in the formation of friendships. Although there are people that take their class status to the extreme, most people fall somewhere in the middle.
After a university research project about social and economic geography, focusing on the interplays student interactions in the dining area during the lunch. We noticed that at those table were there were students who were of different they did not talk together when we were interviewing them. On the other hand tables with students of the same class who did not know each other would communicate with each other and even make jokes while we were interviewing them. My research project was carried out at the University of Zimbabwe