By far, the largest determinant of whether or not you'll be wealthy is the socioeconomic status in which you were born and raised. If you were born to wealthy parents, you stand a good chance of thriving economically. If you were born into poverty, you're likely to live a life of poverty.
Poverty creates all sorts of problems beyond just not having a nice place to live. There's all the stress associated with financial instability, and with stress comes impediments to healthy intellectual growth of the children. Child abuse is far more prevalent in impoverished families, and their neighborhoods are often dangerous, which contributes to stress.
Children raised in poverty are generally unlikely to go on to higher education; many of them don't get a proper foundation that would allow them to thrive in college even if they wanted to go. Schools in poor neighborhoods are terrible.
So the answer isn't in trying to make people smarter; it's in trying to eliminate poverty and making people's lives more stable.
