Doing good for others warms the heart—and may protect the heart, too. Psychologists at the University of British Columbia asked 106 high school students to take part in a volunteering study. Half of the students spent an hour every week for 10 weeks helping elementary students with homework, sports or club activities. The other half of the students did not participate in volunteer work.

Using questionnaires and a medical examination both before and after the 10-week period, the researchers found that students who volunteered had lower levels of cholesterol and inflammation after the study. Those who did not volunteer showed no such improvements.

The health benefits did not correlate to a specific volunteer activity—such as sedentary homework help versus athletics—nor did they link to improvements in self-esteem. But the researchers did find that students who reported the greatest increases in empathetic and altruistic behavior after their volunteering experience also exhibited the most pronounced improvements in heart health. Although more research is needed to untangle how health benefits and altruistic behavior are intertwined, psychologist and study author Hannah Schreier hypothesizes that their findings may reflect a “spillover” effect. “Keeping others motivated could improve your own motivation for healthy behaviors,” Schreier says.

IN CHILDHOOD

Behaving kindly—cooperating, sharing and consoling others—may predict academic success years later, in adolescence.

AS A PRETEEN

Performing acts of kindness may boost happiness and popularity—and reduce the chances of being bullied.

IN ADULTHOOD

Spending money on others is linked to greater increases in a person's happiness than spending on oneself.