Psychological Bulletin, Vol 151(6), Jun 2025, 696-736; doi:10.1037/bul0000481
The extent to which procedural skills involving motor components decay is an issue that has ramifications for skill theory, organizational effectiveness, and individual performance. Prior reviews concluded that longer intervals of nonuse are associated with greater skill decay, but these reviews were based on a modest number of studies, most with short retention intervals. In previous reviews, retention interval has not been investigated as a continuous variable. We report a meta-analysis of skill retention that aims to address these gaps. A search led to the inclusion of 1,344 effect sizes from 457 reports. Random-effects metaregression models were computed with retention interval as a predictor of effect sizes representing changes in performance between skill acquisition and retention. Results indicated that mean differences in SD units grew stronger by 0.08/month for accuracy-based performance measures and 0.06/month for speed-based and mixed performance measures. With lack of use, half of initial skill acquisition performance gains were lost after approximately 6.5 months for accuracy, 13 months for speed, and 11 months for mixed performance. Task type, task complexity, intermittent performance opportunities, and task instructions were identified as possible moderators of skill decay rates. Findings provide researchers with estimates of how much skill decay can be expected if skills are not frequently used and, therefore, when refresher training should be considered. Important methodological considerations for skill retention research were also identified, including the need to isolate retention performance from relearning effects and the need to account for speed–accuracy trade-off functions when interpreting changes in performance over time. (PsycInfo Database Record (c) 2025 APA, all rights reserved)