Reference
Dworak, E. M., Revelle, W., & Condon, D. M. (2023). Looking for Flynn effects in a recent online U.S. adult sample: Examining shifts within the SAPA Project. Intelligence, 98, 101734. https://doi.org/10.1016/j.intell.2023.101734
Review
The Flynn effect, named after the psychologist James Flynn, refers to the phenomenon of a significant and steady increase in intelligence test scores over time. While extensive research has documented this trend in European countries, there is a dearth of studies exploring the presence or reversal of the Flynn effect in the United States, particularly among adult populations. In their recent study, Dworak, Revelle, and Condon (2023) addressed this gap by analyzing the cognitive ability scores of a large cross-sectional sample of U.S. adults from 2006 to 2018.
The authors used data from the Synthetic Aperture Personality Assessment Project (SAPA Project), which included responses from 394,378 adults. The cognitive ability scores were derived from two overlapping sets of items from the International Cognitive Ability Resource (ICAR). The researchers examined trends in standardized average composite cognitive ability scores and domain scores of matrix reasoning, letter and number series, verbal reasoning, and three-dimensional rotation.
The results revealed a pattern consistent with a reversed Flynn effect for composite ability scores from 35 items and domain scores (matrix reasoning; letter and number series) from 2006 to 2018 when stratified across age, education, or gender. However, slopes for verbal reasoning scores did not meet or exceed an annual threshold of |0.02| SD. Furthermore, a reversed Flynn effect was also present for composite ability scores from 60 items from 2011 to 2018, across age, education, and gender.
Interestingly, despite declining scores across age and demographics in other domains of cognitive ability, three-dimensional rotation scores showed evidence of a Flynn effect, with the largest slopes occurring across age-stratified regressions. This finding suggests that not all cognitive abilities are similarly affected by the Flynn effect or its reversal.
Dworak et al.'s (2023) study, makes a significant contribution to the literature on the Flynn effect by providing evidence of its reversal in a large sample of U.S. adults. However, it is essential to consider that the study is based on cross-sectional data, which limits the ability to draw causal conclusions or infer longitudinal trends. Future research could benefit from longitudinal designs to better understand the factors that contribute to the Flynn effect and its reversal in the United States. Additionally, exploring the role of social, cultural, and environmental factors that may impact cognitive abilities could provide further insight into this complex phenomenon.
