Researchers then compared the participants’ responses with physical health information that had mostly been collected in 1992. The researchers also considered the respondents’ socioeconomic status, mental health, social support, marital status and health risk factors, including smoking, body mass index and alcohol use.

The findings showed that those who volunteered for more altruistic reasons had lower mortality rates as of 2008 than people who did not volunteer. Of the 2,384 non-volunteers, 4.3 percent were deceased four years later, compared with 1.6 percent of altruistic volunteers who had died.

However, people who said they volunteered for their own personal satisfaction had nearly the same mortality rate (4 percent) as people who did not volunteer at all.