467 studies and reviews of tapping, visualised — how the research grew, which conditions are best studied, how far around the world it reaches, and how strong the effects actually are.
Published tapping research by year. What started as a handful of case reports in the 1990s is now a steady stream of randomized trials from around the world.
Every bubble is a condition. Farther right = more studies; higher = larger typical effect; bigger bubble = more people studied. Anxiety, PTSD and depression anchor the field.
Tapping has been studied in 43 countries across 9 languages. More than half the studies here — 53% — were run outside the United States, including a deep vein of Indonesian, Korean, Turkish, Iranian and Chinese research that English-only directories miss entirely.
Distribution of the head-to-head effect sizes reported across 30 studies. In this field an effect of 0.8 is considered large — and most tapping studies land at or above it. (Implausibly large outliers, above 3.0, are excluded here, as they are across the site.)
Effect size = Cohen's d / Hedges' g, tapping vs. a comparison group. 0.2 small · 0.5 moderate · 0.8+ large.