In this study, led by the psychologist Sonja Lyubomirsky, people performed five random acts of kindness every week for six weeks. They were randomly divided into two groups: half chunked their giving into a single day each week, and the other half sprinkled it across all five days each week. At the end of the six weeks, despite performing the same number of helping acts, only one group felt significantly happier. The chunkers achieved gains in happiness; the sprinklers didn’t.
