There is an interesting article in this week's The New Yorker, Don't! The Secret of Self-Control by Jonah Lehrer. Interesting, perhaps, because I agree with it.
I have yet to see any sort of good study that links a portfolio of core behaviors (Pattern Recognition, Sustained Focus, Self-control, Empathy, Attentiveness, Curiosity, Imagination, Anticipation, Judgment, Critical Thinking, Prioritization, etc.) to desired life outcomes but I think that slowly, slowly evidence is beginning to emerge that there is a tight causative relationship. Already we know that diligence (work) trumps IQ as does self-control.
We also know that there is a pretty high correlation between degree of reading capability and habits and life outcomes. When you look at that list of behavioral traits, many of them are fostered by the habit of reading. It is not just a function of reading making us more knowledgeable but rather that the act of reading reinforces underlying behavioral traits which foster success.