Working memory training in typically developing children: A multilevel meta-analysis

Working memory (WM) training in typically developing (TD) children aims to enhance not only performance in memory tasks but also other domain-general cognitive skills, such as fluid intelligence. These benefits are then believed to positively affect academic achievement. Despite the numerous studies carried out, researchers still disagree over the real benefits of WM training. With this meta-analysis (m = 41, k = 393, N = 2,375), we intended to resolve the discrepancies by focusing on the potential sources of within-study and between-study true heterogeneity. Small to medium effects were observed in memory tasks (i.e., near transfer). The size of these effects was proportional to the similarity between the training task and the outcome measure. By contrast, far-transfer measures of cognitive ability (e.g., intelligence) and academic achievement (mathematics and language ability) were essentially unaffected by the training programs, especially when the studies implemented active controls (g¯ = 0.001, SE = 0.055, p =.982, τ² = 0.000). Crucially, all the models exhibited a null or low amount of true heterogeneity, which was wholly explained by the type of controls (nonactive vs. active) and by statistical artifacts, in contrast to the claim that this field has produced mixed results. Since the empirical evidence shows the absence of both generalized effects and true heterogeneity, we conclude that there is no reason to keep investing resources in WM training research with TD children.