Otake et al., 2006: Reflecting on kind behavior increased happiness among undergraduates over a week
Otake, K., Shimai, S., Tanaka-Matsumi, J., Otsui, K., & Fredrickson, B. L. (2006). Happy people become happier through kindness: A counting kindnesses intervention. Journal of happiness studies, 7(3), 361-375.Download PDF
Undergraduates asked to reflect on their own kind behavior toward others every day for a week showed significant increases in happiness over this period, while those in a no-treatment control group did not. Randomization was at the class level.