I've heard a lot of people say it's that they don't have a male father figure to teach them, but I don't think that's the main reason
seems more to do with socio-economic factors
Most Helpful Girl
I agree with you that the bigger factor is probably low income and not being able to live in a better area. There's definitely some psychology behind not having a father or mother, but I don't think that alone is significantly reliable in predicting how someone will end up.
There's actually a cool section about this in one of my textbooks:
The average white single MOM household makes about $33,000 (for blacks and Hispanics it's $24,000).
The average white single DAD household makes about $46,000 ($32,500 for blacks, $40,000 for Hispanics).