>>IOW, it is passed to the next generation, but not necessarily by genetics. Could be sheer mentality and attitude.
>
>Not necessarily so.
>Teen pregnancy was the norm for centuries, but the teens were married and supported by family structures.
>When I was a teen (way back!) a twenty-something girl (we could call them "girls" then) who was not married with at least one child was looked at askance. Single women in their 30's were called old maids.

We have both sides of it, in different areas. There's a joke

- What kind of girl should I take, a young one from Belgrade or an old one from Pirot (a city way down south Serbia)?

- The latter.

- OK, but why?

- Because the young one from Belgrade is 45, while an old one from Pirot is 23.

>Unwed mothers were rare and frowned upon. Many gave up their children for adoption.
>Adoption agencies flourished and many of their children found good homes.
>That changed during the 60's and 70's and now unwed mothers with no supporting family structures are ubiquitous and accepted by society at large.
>That shift has had a huge cost.
>Schools have become daycare centers and restaurants for millions of children of unwed mothers.

As one teacher here said, "Education? With our salaries, you should be happy to have just daycare".

>Single mothers without a supporting family structure, not teen mothers, are the issue. I think.

The destruction of family structure is a wider issue, and this part of it is one of the tips of that iceberg. And of course their kids are performing badly - they don't have the adults to learn basic civilization from, the mother being forced to work two jobs just to survive. Mother absent, nobody else available most of the time, where will these kids learn even simple skills others may take for granted (just to mention getting around in a grocery, knowing what products to avoid, handling various automata... all the way to finding their way around an airport, large hotel etc). They never even see those things.

And all this doesn't contradict what I said - the mentality and attitude could well be a product of broken or nonexistent families in which these kids grow (and possibly many of their mothers and unknown fathers come from such milieu as well).