What theory would you relate to family size and education?

I am studying how family size affects education level. What theory would you use? I've looked into conflict, functionalism, symbolic interaction and rational choice.

It's my humble opinion that the more education people hve, the less likely they are to breed like rats!!!!!

That's the opposite of what he's asking. Not, how does education affect family size (number of offspring), but how family size (number of siblings) affects education.

I think.

**Edited for spelling.**

Ohhhhhhhhhhh. I've only one sibling, and we are both college-educated. My husband's the oldest of four, all college education, two with Masters. I haven't gone much past that! HAHAHAHAA!!!

Oh, and I'm not avoiding answering the question. I only understood half of it...if I even understood that part.