Apr 15, 2017 10:32 AM EDT By Ava Jones, UniversityHerald Reporter

A Harvard 80 year old study reveals the secret to living a long, healthy and happy life. The study goes way back to the Great Depression. It shows that those who have happy relationships tend to live a healthier and longer life.

The scientists studied 268 Harvard sophomores in 1938 to find out how to live a healthy and happy life, Harvard Gazette reported. This study, which is a part of the Harvard Study of Adult Development, shows that taking care of ones relationships is as important as taking care of ones health. Only 19 of the people studied are still alive and are all in their 90s.

Two of the people who were part of the study were President John F. Kennedy and Washington Post editor Ben Bradlee. When the study began, the College only had male students, which is why women weren't included. The researchers later on involved the men's children, who are now in their 50s and 60s.

The children of those men now numbers to 1,300. They were involved in the study to help the researchers learn more about how to live a long and happy life. Some of these offsprings became successful lawyers, doctors, and businessmen, while others became alcoholics and schizophrenics.

As the study continues, it later on included more people including 456 people from Boston in the 1970s, and 40 of them are still alive. Ten years ago, the Glueck studies included the wives of the men involved in the Harvard 80 year old study.

There are other studies that show other qualities that would bring happy and healthy lives. A study published in the "Proceedings of the National Academy of Science" observed 8,000 men and women who are 50 years old and above, INC reported. They found that grit and optimism also play an important role for a long and happy life.

See Now: Covert Team Inside Newsweek Revealed as Key Players in False Human Trafficking Lawsuit