James Smith, a health economist at the RAND Corporation, along with others who have studied the circumstances that lead to different group having longevity, have found the education level more than anything else, the International Herald Tribune reports.

The one social factor that researchers have found to be consistent, Smith said, is education which trumps other issues such as race and income, which have been considered big factors.

Smith said that his own research goes along with others that indicate that what can add to a person’s lifespan is more years being educated in a school setting. It can amount to huge benefits decades afterwards, he said.

For example, research papers have evaluated the effects of laws regarding compulsory education in a number of counties such as Sweden, Denmark, England and Wales. In each case, the children that spent more time in school had better health overall, the Tribune reports.

The reasons behind this are based on psychology, researchers believe. It seems that less educated people do not plan as well for their futures or to delay gratification. They are also much more likely to smoke, obviously a big factor in health.

This leads us to other lifespan factors, including smocking; and the association between having a close knit group or friends and family; or feeling that you have control over your occupation, the Tribune reports.