For this review strengths intervention studies were located using online searches and collegial networks and included if they explicitly sought to teach or use a strengths classification to enhance well-being, and used pre- and post-intervention measures and a comparison group. Eight studies met the criteria and have been summarised by this review. To date, the effect sizes achieved by character strengths interventions have been small to moderate.
Quinlan, D., Swain, N. R., & Vella-Brodrick, D. A. (2012). Character strengths interventions: building on what we know for improved outcomes. Journal of Happiness Studies, 13(6), 1145 - 1163. https://doi.org/10.1007/s10902-011-9311-5