Are U.S. adult cognitive ability scores declining over time?
Core argument: Across 394,378 U.S. adults in the SAPA Project from 2006 to 2018, composite cognitive ability scores measured by 35 items were lower each year regardless of education, gender, and age.
Thirteen years of cross-sectional data from a subsample of adults (n = 394,378) were obtained from the Synthetic Aperture Personality Assessment Project (SAPA Project) to examine if cognitive ability scores changed within the United States from 2006 to 2018. Regardless of education, gender, and age, lower annual scores were observed for composite cognitive ability measured by 35 items, and the matrix reasoning and letter and number series scores measured across the 13 years of assessment. A reverse Flynn effect was also present across all levels of educational attainment, with the rate of decreasing scores being steeper for those with less than a 4-year college degree.

