A meta-analysis of 163 studies on meditation in nonclinical adults found medium average effects (r = .28) on psychological variables, not explainable by relaxation or cognitive restructuring alone. Effects were strongest for emotionality and relationships (medium to large), medium for attention, and small to medium for cognitive measures. Results varied by meditation type (transcendental, mindfulness, other). Meditation experience only partially predicted long-term impact. Most of 595 initial studies were excluded due to methodological problems, and many lacked theoretical grounding. The authors call for more precise theories and measurement tools to understand how meditation works.
Equanimity (reduced emotional reactivity) and insight (altered cognitions) are the two key effects of mindfulness meditation that lead to increased wellbeing, according to a model developed from interviews with meditators and refined using Western research and Buddhist scriptures. The model was pilot-tested with a large sample of meditators and non-meditators, showing acceptable fit and significant differences between the groups on the model's core categories. This work builds on a prior meta-analysis that found positive effects of mindfulness meditation on mindfulness, emotions, self-concept, attention, perception, wellbeing, interpersonal abilities, and personality traits.
The authors respond to methodological criticisms of their meta-analysis on meditation's psychological effects. They defend their approach to aggregating effects across variable categories and maintain that transcendental meditation (TM) studies show some upward bias, even using the critics' preferred method. They concede they missed some TM studies but argue this omission did not alter their conclusions. The piece concludes with suggestions for improving future meditation research.