I think there's no real doubt that conception when each gamete contributor is in less than optimum health to produce a healthy intelligent child is a demonstrable problem. There are too many kids essentially uneducable because they haven't the ability for sustained attention, retention of learned material, regulation of emotion etc. Then they get shunted in special ed and drop out after years of failure and frustration.

But civilizations were built and sustained for millennia when populations had nothing optimum at all, really; there are always smart inventive people born despite the worst conditions.

So it always boils down to parenting. You don't need a GED to talk to your child; to sing; to make silly word games. God knows the culture of rap involves rhythm and wordplay. Choice of words is of course meaningful here, if by the time a kid is five he knows bitch and cunt and fuck you etc. etc. but has no clue that there are dozens of ways to describe the color blue, we can pretty much predict his life trajectory.

I myself had books, but sitting at the table I'd read anything including juice cartons and the ketchup bottle if I couldn't read something of more value at mealtime, and therefore basic literacy materials are always at hand for anyone.

What soured me permanently on social welfare whining was living in a desperately poor highly socially stratified country for awhile, and I saw parents who had no realistic hope of their children getting anywhere, because of poverty or religious minority status etc. etc. nevertheless sacrifice greatly to enable kids to go to shitty primary schools, needing to wash the one school uniform daily because they couldn't afford more.

Compared to them every inner city in this country is paved with gold.