Jonah Lehrer, one of my favorite neuroscience writers in in the popular press writes:

Children who could better regulate their impulses and attention were four times less likely to have a criminal record, three times less likely to be addicted to drugs and half as likely to become single parents. In many instances, the ability to utilize executive control was more predictive of adult outcomes than either IQ scores or socioeconomic status.

This is an interesting perspective. While he doesn't mention mindfulness by name, it's essentially what he's talking about. Specifically, he's referring to the aspect of mindfulness that helps manage attention. Developing ability to choose where to focus your attention seems to have benefits across the lifespan.