two cents -
I agree with you. It does seem that that the more dysfunctional a family is the more kids they have. I worked for Child Protective Services for many years and currently oversee foster homes (just because I don't like kids doesn't mean that it is their fault they got stuck with crappy parents and deserve to be treated like shit)....
this is what I have seen....
Dysfunctional people tend to more easily fall into the thought pattern so many breeders do when deciding to have kids (note the term DECIDING instead of got knocked up in the back of a car except I guess it could still be applied to then why they don't have an abortion).... these are things like...
My child will be special, my child will show the world I am worth something, my child will have the things I didn't, my child will be great, my child will carry on the family name, my child will "fix" the marriage problems I have because it will bring us together, my child will give me someone to love who will love me back, blah, blah, blah. (Keep in mind there are also the dysfunctional people who give no thought as to why they should have a kid other then well I'm knocked up and my momma had 10 kids and my sister got pregnant at 14 so I guess it's my turn).
I believe that dysfunctional people have the most kids because they are dysfunctional and in being that way are unable to recognize their own selfish and sometimes ignorant reasons for allowing themselves to get pregnant or for thinking that having a kid will make thier lives better or more meaningful. Let me tell you, their lives sure looked meaningful when I worked for CPS and was over removing a breeders eight damn kids from her because she was high all day or hooking herself out or beating her kids and not feeding them. I have worked in social services for almost 10 years and I have delt with more breeders then I can count. And pretty much all of them were dysfunctional.
Sorry, that sure was a long reply to your question!