Comes down to impulse control. To be fair and steer it away from being a racial thing, I've got two nieces that keep pumping out kids and are suckling off the government teet. One has no contact with the father of her children while the father of the other neices babies is in prison.
In comparison, the nieces from my other sister were raised in a structured nuturing enviornment, and are the same age as the fools but have no kids and are in college about to graduate. In the end, it's about raising them right.