Over the years, social scientists who have conducted careful reviews of the evidence base for diversity trainings have frequently come to discouraging conclusions. Though diversity trainings have been around in one form or another since at least the 1960s, few of them are ever subjected to rigorous evaluation, and those that are mostly appear to have little or no positive long-term effects. The lack of evidence is “disappointing,” wrote Elizabeth Levy Paluck of Princeton and her co-authors in a 2021 Annual Review of Psychology article, “considering the frequency with which calls for diversity training emerge in the wake of widely publicized instances of discriminatory conduct.”

Dr. Paluck’s team found just two large experimental studies in the previous decade that attempted to evaluate the effects of diversity trainings and met basic quality benchmarks. Other researchers have been similarly unimpressed. “We have been speaking to employers about this research for more than a decade,” wrote the sociologists Frank Dobbin and Alexandra Kalev in 2018, “with the message that diversity training is likely the most expensive, and least effective, diversity program around.”