Shifting Minds: A Quantitative Reappraisal of Cognitive-Intervention Research

Recent popular areas of research in psychology suggest that behavioral interventions can have profound effects on our cognitive abilities. In particular, the study of brain training, video gaming, mindset, and stereotype threat all include claims that low-cost, noninvasive manipulations of the environment can greatly affect individual performance. Here, I provide a quantitative reappraisal of this literature, focusing on recent meta-analytic findings. Specifically, I show that effect-size distributions in the four aforementioned areas are best modeled by multiple rather than single latent distributions, suggesting important discrepancies in the effect sizes reported. I further demonstrate that these multimodal characteristics are not typical within the broader field of psychology, using 107 meta-analyses published in three top-tier journals as a comparison. The effect-size distributions observed in cognitive-intervention research therefore appear to be uncommon, and their characteristics are largely unexplained by current theoretical frameworks of cognitive improvement. Before the source of these discrepancies is better understood, the current study calls for constructive skepticism in evaluating claims of cognitive improvement after behavioral interventions and for caution when this line of research influences large-scale policies.