It's been interesting watching Green Bay integrate over the past years. The curious fact from which we start is that GB had almost no minority people other than Oneida and Menominee for a ridiculously long time. When I was in high school, I'm pretty sure that there was exactly 1 black student among the 1600 or so. He was integrated by default. (The Native Americans in the city were substantially integrated, too, with a low-grade but continuous level of prejudice.) Other minorities had bypassed Green Bay to a surprising degree.
When I moved back to Green Bay 25 years ago, this was only just starting to change. Schools became integrated at a faster rate than the population as a whole, and I watched parents struggling with the twin issues of prejudice and discrimination among their children a generation ago. The other adults were able to ignore the issues for a while longer. I should note that the first major minority influx was of Hmong refugees, which occurred much more quickly than changes in the Black and Hispanic groups. That probably had some influence on how the community responded, since Hmong were considered strangers but did not arrive with the baggage of criminal association. That is, Hmong gang membership only became an issue later, whereas Blacks might be seen as potential gang members and drug dealers as soon as they moved to town.
Today we've finally arrived at some modicum of an integrated community. There are various minority homeowners across my neighborhood -- still not many, but you do see them in their yards, talking to neighbors, walking and driving down the street. It would now be difficult to believe that GB doesn't have any significant minority populations, although I'm sure that some older residents hold that idea as their working hypothesis. My impression is that those white adults who have lived here for years are generally aware of the issues of racism and prejudice and desirous of avoiding those problems. There are, of course, exceptions. My neighborhood also includes a pickup truck with white pride and Hatebreed bumper stickers.
People behaving differently from people of our past experience are noticed. That is both natural and prudent and not, in itself, an indication of prejudice or discrimination. At the same time, being noticed and wondered about makes any person more vulnerable to prejudice. I remember my former neighbor classifying the kids who lived behind me as being "hooligans" -- despite their being white and polite and not walking on her lawn. She probably put that label on them because they were more visible and audible than she expected. When you see someone or something which doesn't exactly fit within your category of normal, your brain attempts to fit some other established category. If the neighbor boy doesn't look or act like a "nice" boy, and you have a category of "hooligan", you will test whether your observations fit "hooligan" better than "nice". (Neither of those categories work for me, or even denote anything meaningful to me.) If there is no category available to you, you will be open to your friends and neighbors suggesting a classification for you to use.
Until you find a classification that fits your knowledge, the observations nag at the surface of consciousness. And that is always uncomfortable.
There is a tendency for minorities to be more common in older and poorer neighborhoods of GB, which reinforces some of the continuing prejudices. Many of my neighbors have prejudices about poor people which are entirely separate from racial and ethnic prejudices. (Some of them may also have prejudices about rich people.) I can imagine people in GB saying, "We all know that crime is rampant along South Maple Street and always has been." Or Day Street or Jackson Street. They might also ask, "Why would anyone move there, unless they are criminals too?" That would be prejudice, but not racial or ethnic prejudice. (It is in line with the question, "Can anything good come from Nazareth?") To the extent that identifiable racial and ethnic groups live more frequently in these areas, the geographic prejudice becomes also a racial or ethnic prejudice.
I would contrast this prejudice about South Maple Street with the prejudice that no drug dealers live on my street. I live on a nice street (whatever that means) and it may be true that there are no dealers living here now. But I'm quite confident that there was one living directly across the street from me a few years ago. The police visits were one sign, and the cars which drove up in the middle of the night another. Fortunately for our property values, reality hasn't deeply affected the prejudgement about my neighborhood.
Recently I've noticed groups of minority youth, mainly boys and (in my neighborhood) more often Black than Hmong of Mexican. These gatherings are not infrequently larger, noisier, and rowdier than the groups of kids we became accustomed to over the prior 40 years, a fact which reinforces another, overlapping set of fears and prejudices. One such group was worrying some neighbors around the corner from me on a recent evening. The neighbors told me that the group had been waiting for a fight; maybe they were, but all I saw was a typical end-of-summer bunching of teenagers.
Of course, many people have prejudices about teenagers which are distinct from any racial and ethnic prejudices. Most adults are a little bit afraid of teenagers. (This is often in spite of wishing to be like them.)
Like geographical prejudices, age-related prejudices can easily merged with other categories of pre-judgement. A Mexican teenager from the poor side of town is more quickly categorized as evil and dangerous than a middle-aged Hispanic professional living just a little bit upscale from me. We can still prejudge the professional, but it takes a little bit more work to do so and our judgement is a little less confident than in the case of those rowdy boys and trashy girls.
Teenagers we actually know, Mexicans we actually know, Blacks we actually know are for the most part exceptions to the general prejudgement. One might think this reality would trump the prejudice, but that is not the case in general. Reality only applies to the individuals we know. Predjudice applies to all people we do not know, those about whom we do not have enough direct knowledge to treat as a part of our personal reality.