I’m no expert on this subject, but I’ll share what I observed as a teenager working on my dad’s real estate maintenance crew in Roxbury MA during the 60’s. During that time a large influx of blacks moving up from the southern states rapidly changed Roxbury from a mixed catholic/jewish/black neighborhood of Boston to the almost exclusively black enclave that it remains to this day.
Anyways .....
Black families moving up from the south arrived essentially penniless and without the necessary education to obtain decent paying jobs. Many or most consequently ended up on welfare.
These people may have lacked somewhat in the way of education, but it rapidly became clear to them that they could obtain a higher rate of benefits if the parents were “separated” in the eyes of the bureaucrats and filing separately for benefits. This required that the parents no longer inhabit the same residence, so the husband would leave and rent his own apartment. The social workers would actually prowl around checking to make sure that husband and wife were not “cohabiting”.
IMO, this is the point where the Law of Unintended Consequences took over. The institution of marriage and the two parent family became slowly discredited as a result of badly crafted federal welfare regulations making it financially disadvantageous to maintain. I’m sure that this is not the only factor in play, but I do believe that it does bear a full share of responsibility for the breakdown of the family among the poorest sectors our our populations.
The legislation may have been badly crafted, but I think it was a deliberate attempt to harm the black family. If you offer temporary help to people who are literally moving out of poverty, in a few years they don't need your help any more. If you deconstruct the family, provide bad schooling and other things, you keep generations of people in a cycle of poverty. You offer them a little "help" while keeping them down and the more you keep people down, the more they think they need your "help." It is really a diabolical system.
George Wallace made the same observations about people moving to urban areas without the preparation for life in urban areas.