Objectives Interventions involving kindness- and compassion-based meditation (KCBM) have been shown to have various benefits for adults, and there is growing interest in using KCBMs with children. This systematic review explores the effects of KCBM on wellbeing, prosociality, and cognitive functioning in children and adolescents. Methods Studies were eligible if they examined interventions that contained a proportion of KCBM above a set threshold, included child participants only, used any or no control group, and included at least one outcome measure related to wellbeing, prosociality, or cognitive functioning. Studies were assessed for quality using the Quality Assessment Tool for Quantitative Studies, and findings were synthesised narratively. Results A systematic literature search of 11 databases up to February 2020 identified 3,073 papers. Ten studies were eligible for inclusion in the review, including 807 children. There was evidence of improvements in wellbeing in 47% of wellbeing outcome measures (including stress, anxiety, depression, negative affect, markers of inflammation, mindfulness, and self-compassion). Prosociality and cognitive functioning (visual perception and motor accuracy) were examined in 1 study each, and there was evidence of improvements in both outcomes. Effect sizes ranged from small to large. There was some evidence that interventions were more effective with younger, non-clinical populations and where intervention teachers were experienced. Study quality was generally weak. Conclusions There was no strong evidence base for positive effects of KCBM with children. However, the findings of the review are encouraging given the early stage of development of the field, and further research is warranted. Recommendations for future research include more robust methodological design, improved reporting, and a focus on developmental mechanisms of change. Systematic Review Registration PROSPERO CRD42014013065.

Although there is much interest in the development of prosocial behaviour in young children, and many interventions that attempt to cultivate kindness in children, there is a paucity of research exploring children’s lived experiences of kindness and including their voices. In this study, children’s understanding of kindness is approached through qualitative interviews using puppets. Interviews were conducted with 33 children aged 5-6 years in 3 schools in the United Kingdom. Through thematic analysis, 4 themes were developed: (a) doing things for others, (b) relating with others, (c) rules and values, and (d) kindness affects us. These themes are examined in light of current thinking on prosocial and sociomoral development, and several key insights are highlighted, including types of prosocial behaviour, social connection, kindness-by-omission and defending, in-group bias, universal kindness versus personal safety, self-image, and a desire to improve the condition of society. These findings have implications for future research on prosocial development and for the design of kindness-based interventions, as well as providing an ecologically valid method of inquiry for use with young children.