A narrative review of the consistency, rigor and generalizability of experiments on prosocial behaviors and happiness

Past experimental research shows that prosocial behavior promotes happiness. But do past findings hold up to current standards of consistent, rigorous, and generalizable evidence? In this review, we considered the evidentiary value of past experiments examining the happiness (i.e., subjective well-being; SWB) benefits of prosocial action, such as spending money on others or acts of kindness, in non-clinical samples. Specifically, we examined: (1) how consistent findings are across meta-analyses, (2) the conclusions of pre-registered, well-powered experiments, and (3) if the SWB benefits of prosociality are detectable beyond WEIRD (White-Western, Educated, Industrialized, Rich, Democratic) samples. Across the two meta-analyses we found, prosocial behavior led to a small consistent increase in happiness, yet estimates were based primarily on underpowered and WEIRD samples. We identified a growing number of pre-registered experiments (19/71 conducted to date), in which: (1) roughly half were well-powered; (2) only two recruited non-WEIRD samples, both underpowered and collectively showing mixed results; and (3) most examined prosocial spending (79%) over other prosocial behaviors, with happiness gains observed most consistently in well-powered studies on prosocial spending. Finally, we found that just 19% of all experiments recruited non-WEIRD samples, most of which were underpowered and presented mixed results, with acts of prosocial spending demonstrating the most consistent evidence of happiness benefits. We join other researchers in urging for more well-powered pre-registered experiments examining various prosocial behaviors, particularly with Global Majority samples, to ensure that our understanding of the SWB benefits of prosociality are firmly grounded in solid and inclusive evidence.