The most successful, caring, well educated and thoughtful people I know came from the worst upbringings. They grew up in households with abusive parents, homelessness as a child and general chaos.
At the same time the biggest burnouts, felons, drug-addicts and the like that I know personally (and in the statistics) came from ... the worst upbringings. They grew up in households with abusive parents, homelessness as a child and general chaos.
On the flip side, most of the people I know who were raised in peace, calm, consistent love, and wealth are generally pretty middling and while they live a fine life aren't really making huge impacts as I see from group 1 above. Maybe it's that the story isn't as compelling so we don't read about those as much. Chalk it up to sampling error.
From a social scientist perspective, group 3 is the ideal upbringing because it's consistent and the lower bound outcome is generally still desirable.
However there is just something about the ridiculous struggle that seems to either make diamonds or spent coal. From the perspective of population distribution for groups 1 and 2 it's overwhelmingly spent coal that comes out, but that 1% that becomes diamonds are really spectacular.