I know a dad who was 12 and his girlfriend was 15. So by the time the baby was born, he was 13 and she was 16. Which is pretty much the same thing.
Of course the parents of both kids were on various forms of state and federal food and welfare aid and SS disability payments, yet the kids parents weren't too disabled to keep from having lots more kids even younger than these were.
So is it any surprise at all that these kids are going to run around the neighborhood unsupervised and do the same exact thing the parents did? In these cases I just can't blame the kids at all for emulating their parents poor social values.