The far-from-conservative Brookings Institution has a research report concerning a character trait positively associated with both achievement in later life and with social class for males. The trait is "An inclination to try hard, despite no obvious extrinsic motivation." In other words, the trait is intrinsic motivation.
Males from affluent homes have more of it than others. The table captioned Family Income Quintile in Adolescence shows the extent to which people from each of the income quintiles exhibit this trait. It is a "staircase" with values of 22%, 33%, 41%, 46%, and 55% for the five income quintiles, ranging from low income household to high income. No statistical test is necessary to see a strong positive correlation.
Author Richard V. Reeves shows he understands the inability of correlational studies to demonstrate causality. He indicates one or both of the following may be true: Affluence creates motivation; or motivation creates affluence.
