Schooling, Intelligence, and Income

In this article, the authors examined the evidence for linkages among 3 variables: schooling, intelligence, and income. They concluded that intelligence and schooling have a bidirectional relationship, with each variable influencing variations in the other. Moreover, changes in both schooling and intelligence influence variations in economic outcomes. Although any single study of the interdependency of these 3 variables can be criticized on the grounds that the data are correlational--and consequently are open to alternative interpretations--when viewed together, the evidence for their linked causality is quite convincing: Each increment in school attendance appears to convey significant increases not only in economic and social returns but also in psychometric intelligence. Thus, the value o f schooling appears to extend beyond simply schooling's direct effect on income.