Not necessarily; he might just mean that parents who did poorly in school are more likely to raise children who also do poorly in school. Some people and cultures value education, and some don't, and they tend to pass that on to their children.

I saw this myself growing up, as my extended family on my mother's side were white, rural people, who weren't educated and didn't value education at all. Luckily she kept me away from them most of the time and pushed me to do well in school and go to college; I was the first person in her family to finish college as a result. If I had spent all my time growing up with my cousins, that probably wouldn't have happened.

As for reproduction, many of those poorly-educated cousins went on to become teenage parents...