Table 2.

Small to moderate well-being effect sizes in positive psychology intervention meta-analyses.

Outcome	Effect size
Well-being	g = 0.28 (Van Agteren et al., 2021) g = 0.39 (Carr et al., 2020) g = 0.40 (Geerling et al., 2020) d+ = 0.325 (Carrillo et al., 2019) SMD = 0.36 (Lomas et al., 2019) r = .10 (White et al., 2019)δ = 0.28 (Curry et al., 2018) g = 0.24 (Chakhssi et al., 2018; Dickens, 2017) g = 0.46 (Theeboom et al., 2014) g = 0.52 (Mazzucchelli et al., 2010) mean r = .29 (Sin and Lyubomirsky, 2009)
Subjective well-being	g = 0.34 (Hendriks et al., 2020) d = 0.22 (Koydemir et al., 2020) g = 0.24 (Tejada-Gallardo et al., 2020) g = 0.48 (Hendriks et al., 2018) SMD = 0.34 (Bolier et al., 2013)
Psychological well-being	g = 0.39 (Hendriks et al., 2020) d = 0.08 (Koydemir et al., 2020) g = 0.25 (Tejada-Gallardo et al., 2020) g = 0.40 (Hendriks et al., 2018) d = 0.31 (Davis et al., 2016) d = 0.44 (Weiss et al., 2016) SMD = 0.20 (Bolier et al., 2013)