While the stress of goal achievement gives individuals the ability to complete higher levels of education and meet other goals, chronic stress (that typically experienced by the poor) makes it hard to plan beyond the moment. The Brooking Institute's Carol Graham takes a look at the effects of stress on social mobility.
Graham found that the gap in stress between the poor and the rich to be great in more unequal cities. She also found that the negative coefficients of stress were greater than the positive coefficients of key correlates of well-being:
Adding interaction terms for stress and income and stress and education, we find that higher levels of income or education mitigate the negative effects of stress on life satisfaction. It may be that income and education simply makes it easier to manage stress...Not only do the rich have better incomes, they may have better stress.