Currently, in the United States, there are huge racial disparities in cognitive functioning and the prevalence of cognitive disorders like dementia. The investigators in this study were interested in studying how income (e.g., salary, wages, and other earnings) and wealth (e.g., one’s accumulation of economic resources including saving, investments, and material possessions) might account for these differences. They hypothesized that income and wealth would be significant contributors to the differences in cognition between Black and White people. They also hypothesized that the impact of income and wealth on cognition would differ depending on people’s age. To test their hypotheses, the authors utilized data from a large national survey and conducted a number of elaborate regression analyses aimed at determining the factors that would account for Black-White disparities in episodic memory, executive function, and overall cognition. In addition to measuring income and wealth, they also accounted for other factors that could contribute to cognition such as childhood environment, educational attainment, and marital status. What the researchers found were intriguing. First, there were Black-White disparities in overall cognition, executive functioning, and episodic memory; however, the magnitude of these disparities lessened with age (meaning that group differences were smaller among older adults). Childhood environment and education were much stronger predictions of racial disparities in cognition than income. However, wealth was an important predictor of Black-White cognitive disparities, particularly for older Americans (i.e., at age 80 and older). The fact that income measures the flow of financial resources during a particular time period whereas wealth is cumulatively built, often over multiple generations, suggests that these disparities may be challenging to reverse.
