Happy to help? A systematic review and meta-analysis of the effects of performing acts of kindness on the well-being of the actor
With Oliver Scott Curry, Lee Rowland, Sally Zlotowitz, John McAlaney and Harvey Whitehouse
Does being kind make you happy? Recent advances in the behavioural sciences have provided a number of explanations of human social, cooperative and altruistic behaviour. These theories predict that people will be ‘happy to help’ family, friends, community members, spouses, and even strangers under some conditions. Here we conduct a systematic review and meta-analysis of the experimental evidence that kindness interventions (for example, performing ’random acts of kindness’) boost subjective well-being. Our initial search of the literature identifies 428 articles; of which 19 (21 studies) meet the inclusion criteria (total N=2,685). We find that the overall effect of kindness on well-being is small-to-medium (d = 0.36). There is also some indication of publication bias – lower quality studies tended to find larger effects – suggesting that the true effect size may be smaller still (0.29 ≤ d ≤ 0.33). We recommend that future research: distinguish between the effects of kindness to specific categories of people; take kindness-specific individual differences into account; and consider a wider range of distal outcome measures. Such research will advance our understanding of the causes and consequences of kindness, and help practitioners to maximise the effectiveness of kindness interventions.