We all know that it’s good to be kind to others. Kindness is an important virtue. It also sustains relationships and helps us build a trusting and cooperative society. You may have also heard that kindness makes you happier and healthier. But what does that mean for you? What acts of kindness will make us happiest, and who tends to benefit the most? A newly published review of decades of kindness research provides some answers. In this paper, researchers analyzed the results from 126 research articles looking at almost 200,000 participants from around the world. The studies they chose all had to meet certain criteria, such as including only adults and reporting good statistical data; some were experiments, where people did a kindness practice to observe its effects, while others just surveyed people about how kind and happy they were. The studies measured well-being in a variety of ways, including both mental and …