Confusion, on this topic reigns!
The neighborhood I live in is quite diverse in the make-up of its occupants. We have, in a 50 house neighborhood, families from China, The Philippines, Tibet, Africa, India, and Taiwan; we also have American-born residents who are ethnically Mexican or Italian, or of Northern European descent. It has to be, that many of these people chose this neighborhood because of a personal value on diversity (there are nearby neighborhoods that are homogeneous in their make-up). And, yet, there are lots of disagreements on how to conduct the business of the Homeowners' Association due to cultural differences. People get offended sometimes just because of a perceived attitude on the part of a neighbor who, after all, did grow up in a completely different way, with a whole different set of assumptions.
So, what about this contradiction---being fascinated by differences, even romanticizing them, on the one hand and, on the other, bristling and becoming defensive over the smallest unintended slight? Some anthropologists have theorized that this is all genetically explainable. Being able to pick up difference helped humans of earlier times to spot their enemy, primarily. However, we also needed to be able to spot a small animal in a large, complicated landscape, if we were hungry.
Genetic differences are good for creating healthy babies. (In fact, a study was done where women were able to pick out men whose immune systems were different from theirs---an advantage for potential off-spring---they were more attracted to the smell of those mens' t-shirts...!)
This opposition within may, in fact, be built in. But, sometimes it can be harmful. De-valuing someone for making a minority choice (such as a healthy person who chooses not to bear a child) can be an unnecessary burden to that person who has to answer intrusive questions over and over---to feel obligated to explain themselves. "To not have children is a choice, not a disease or a deficit..."More Magazine (2-year) Nanette Varian.
Another unfortunate result is the tendency to categorize others so as not to have to deal with their individuality (isn't that what's so interesting about others?). It can be dismissive as in the Ageism that is ubiquitous in the United States. As people age, they do begin to look more alike; they (we) all eventually have the same color of hair---gray. Our features become softened, less sharply defined. Even, the differences between women and men become less striking. However, by lumping all of the elderly together in one convenient box (incidentally, as people age, although they look more alike, they generally become more differentiated and individuated psychologically),--- readily making an assumption about them depending on your cultural expectations (for example: Oh, there's a group of older people, they must be wise, or, as in the typical American mind: Oh there's a group of senior citizens, I won't waste my time on them),--- we are missing something.
I hope that my propositions about the inconsistency of human nature regarding difference has given you some food for thought.
Please comment below.