I've actually thought about the whole crime/drugs/out of wedlock births -- fall of civilization thing -- a lot. The only conclusion I've come to is very "squishy" and unquantifiable. That is, if a guy believes that tomorrow is gonna be even marginally better than today, then he's less likely to engage in criminal activity than a guy who believes that tomorrow is gonna be the same old, same old or a little worse.
I won't disagree with you, but it does point to what I have said. Many people in poverty are trained today to think it will never be better or that they cannot escape it. They rely on welfare for basics and think that drugs and such are their only hope.
Their real hope to escape both poverty and high crime rates is for them to learn and see that the only real hope is to work hard and pull themselves out of it, like many of us have had to do.