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.
Category: Social Issues
The scope of racial disparities in test scores in the United States
The purpose of this post is to provide a comprehensive overview of racial and ethnic disparities on cognitive and academic tests in the United States. The primary focus is on black and white Americans because most data focuses on comparing these groups, but I’ll also mention disparities for other groups (mainly Hispanics and Asians) when such data is available. I start by reviewing data on the magnitude of racial disparities in cognitive ability. Next, I consider racial disparities in other kinds of tests, including college admissions and academic achievement tests, finding that these disparities are about as large as disparities in cognitive ability. Then, to better contextualize the magnitude of racial disparities in test scores, I compare racial gaps to gaps between other groups, such as students from different countries or different levels of socioeconomic status. Finally, I present data on the ubiquity of test score gaps, showing that the gaps persist through all levels of education, across all geographical units of analysis, and across all socioeconomic levels.
Analyzing racial disparities in socioeconomic outcomes in three NCES datasets
In a previous post, I cited several studies showing that racial disparities in many important social outcomes are largely driven by racial disparities in cognitive ability. This post will expand on those findings by demonstrating similar patterns in 3 nationally representative datasets that I have not yet considered elsewhere. The datasets include data on socioeconomic outcomes from the early 1990s to early 2010s. I will examine how racial disparities in educational attainment, occupational prestige, and income (the three primary measures of socioeconomic status, as explained here) are related to various factors such as parental income, high school academic achievement, and family structure. My main focus is on disparities between blacks and whites, where I find that the vast majority (over 90%) of the adulthood income gap is explained by some combination of the aforementioned factors, and virtually all of the disparity in educational attainment and occupational prestige are explained by high school achievement.
Parental SES vs youth cognitive ability as predictors of socioeconomic outcomes
In this post, I will review studies that compare the predictive validity of youth cognitive and parental socioeconomic status (SES) on future socioeconomic outcomes based on large national representative longitudinal samples in the United States, United Kingdom, Sweden, Norway, and Germany . The measures of both parental SES and socioeconomic outcomes are primarily comprised of educational attainment, occupational attainment, and income. The studies converge on the conclusion that youth cognitive ability is by far the superior predictor of socioeconomic outcomes.
Predictors of academic achievement
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.
Racial disparities in intergenerational mobility
In this post, I explore racial disparities in intergenerational mobility, i.e. racial disparities in offspring outcomes after controlling for parental achievement on the same outcome. The primary focus is on black-white disparities in income mobility, i.e. the finding that black children have lower incomes than white children with similar parental incomes. However, other racial groups and socioeconomic outcomes will be considered when data is available. I start by documenting racial disparities in various socioeconomic outcomes, such as income, educational attainment, and wealth. I also show that there are also large racial disparities in mobility for each of these outcomes. Next, I document some of the patterns of income mobility gaps in more detail, by showing the history of the gap, how the gaps vary by sex, and making comparisons with racial groups other than blacks and whites. Following that, I explain why differences in income mobility are pivotal to explaining persistent income gaps between blacks and whites. I then consider a number of different factors that might explain black-white gaps in income mobility. Finally, I end by considering what I take to be important implications of these findings.
The causal influence of cognitive ability
In a previous post, I cited data showing that cognitive ability is significantly correlated with various important outcomes, such as academic achievement, occupational performance, socioeconomic status, anti-social behavior, and health. However, that data only establishes that there is a statistical association between cognitive ability and these outcomes. The data does not establish that cognitive ability has a causal influence on any of these outcomes. In this post, I will provide evidence that cognitive ability has a causal influence on academic achievement, occupational performance, socioeconomic success, and anti-social behavior.
Causal inference in social science
The purpose of this post is to provide some guidelines to aid in inferring causation in social science research. At the moment, the post just defines confounding variables, distinguishes them from other third-variables (e.g. mediators and colliders), and provides some examples of statistical techniques that can be used to control for confounding variables. In the future, I hope to cover in more detail regression analysis, causal diagrams, multicollinearity, and other concepts important to understand to infer causation in the social sciences.
The predictive validity of cognitive ability
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.
Interpreting Effect Sizes
Note: this post is a work in progress. The effect size is a statistic that quantifies the magnitude of the association between two variables. It is arguably the most important statistic reported in any study attempting to report the relationship between different variables. This purpose of this post is to aid in interpreting effect sizes, particularly from a social science perspective. There are several different kinds of statistics that are used to report effect sizes, […]