Anecdotely, I remember the kids who were suspended in school and they tended to be the poorest kids. Very seldom was a middle-class or rich kid suspended. In our case, however, we were given the option of performing "work" after school to avoid suspension i.e. cutting the grass. This was to avoid getting zeroes for the tests that were missed. The poor kids never seemed interested in that. They just took the days off. I was friends with one of the kids (druggie) and he told me the days off were preferred because they had to pass him anyway. Since they couldn't flunk him and he didn't care about his grades, he stayed at home and smoked dope when he got suspended while his mom worked. Win-win in his eyes.
Oddly, he told me that the teachers gave him F's but the principal always changed the grades so he would pass. A high number of kids flunking looked bad for the principal.
Another elementary school friend was active in scouts when I returned to San Diego in 1969. He was doing fine until he tagged up with the druggies and smokers. He had an illigitimate kid and never managed to graduate from high school. His dad was a Lt in the Navy and lived and a slightly nicer house than my own a couple blocks away.
I could writes volumes of anecdotes describing perfectly nice middle class white kids that grew up to be below average performers. Not criminals, but just barely productive enough to stay off welfare.
As with any distribution, you have success and failure. The class president and valedictorian was Valerie Zavala. She lived two doors down from my house. She earned a PhD at Harvard. We only had ONE valedictorian when I graduated. No need to assuage the egos of 10+ people. There was a number one and she was the genuine article. She is apparently the nightly news magazine anchor at PBS station KCET in Los Angeles now.