just for example what do you think the world view is of the children in this neighborhood? and could this be a typical way many police forces in the south make their statement to the black neighborhoods on their place in the pecking order. They have been using fear to keep them in their place for 150 years.

Sometime around 3rd grade, perhaps very late 2nd grade, they start becoming divided. Usually under the influence of older siblings. "Why are you hanging out with that kid?" The first graders are an undifferentiated mass.

There's a lot of pressure to start conforming to in-group practices and norms, with older kids taking siblings and others under their wings. At that point the kids face a decision: Do I get accepted by my older siblings' peers or face rejection? It's rough on minority kids because then they have to choose which group norms to abide by. Do they assimilate to the majority, and seek approval that way? Or do they stick with their group's norms because when they get to a larger setting there'll be a group for them to be in?



Around middle school, beginning seriously in 6th grade and finishing up a couple of years later, "identity" formation is a big deal according to the psych research. Pressure to conform is then pretty universal. Those who were outliers in terms of in/out group boundaries tend to start being reeled in. Some hold out for a while, but most start acting in conformity with "their" group. They're often race-based, because that's the tradition. If you read the literature on schools, you find that there's a large group of scholars who argue that this is a good thing--the question is usually phrased, "Why do all the black kids sit at the same table?" and the answer is usually identity, group cohesion against outside threats, both preparing them for the racism that they will encounter and teaching them to spot racism and threats. The assumption is that the most important identity, what students should have as defining themselves first and foremost, is race and the correlated culture (if you're non-white).

What literature exists that doesn't say instilling deep racial divisions in the student body at that point isn't good goes agnostic.

For large cohorts the groups are fairly quickly stratified by class or neighborhood or other social affiliation. For small communities, they're not. Those whose base identity isn't predicated on race tend to have troubles later with "their" peers. (The assumption is that if you're black and wealthy, your "real" peers are black.)

A bit later individual identity is formed, once group identity is in place. Then you have problems because in a small community group cohesion gets enforced really strongly, and when there are interethnic tensions the group boundaries become highlighted. So if an individual's identity strays from the pack's, that individual has social problems.