In this post, I will review studies comparing the predictive validity of cognitive ability and parental socioeconomic status (SES) on academic achievement. Parental SES is usually measured via some combination of parental income, educational attainment, and occupational status. Academic achievement is measured either through grades or achievement test scores. A clear picture emerges from each study cited in this post: cognitive ability is a far superior predictor of academic achievement than is parental SES.
The purpose of this post is to cite predictors for academic achievement. I will focus on merely listing effect sizes rather than synthesizing the research.
There is overwhelming evidence showing the predictive validity of cognitive ability for important life outcomes. Cognitive ability measured as early as age 6 has a strong association with one’s future success in a number of important outcomes, including academic achievement, occupational performance, income, educational attainment, occupational prestige, criminality, self-control, and health. The associations are typically large, often making cognitive ability the best predictor for such outcomes. In this post, I will cite research showing this evidence. I will begin with some background on cognitive ability, including definitions, the distributions of IQ test scores, the stability of cognitive ability test scores, and expert consensus on the validity of cognitive ability. Finally, I will cite data demonstrating the predictive validity of cognitive ability in academic achievement, occupational performance, socioeconomic success, anti-social behavior, and health.