To measure “control beliefs,” participants reported how much they agreed with statements on their sense of “personal mastery” and “perceived constraints.” The former included statements like “I can do just about anything I really set my mind to,” and the latter had statements like “What happens in my life is beyond my control.”

The researchers got mortality data on the people who completed this survey from the National Death Index. They looked at the data over 14 years—from 1995 to 2009. In analyzing the data, the researchers first controlled for demographics, then for both parental and participant levels of education, and finally control beliefs.

Results: The data indicated that older male minorities were most at risk for dying. Parental education levels did not seem to affect mortality, but the participants’ own education did: each standard deviation increase in education (such as “from high school to an associate’s degree,” the study helpfully explains) decreased mortality risk by 17 percent. Having a stronger sense of control over one’s life reduced the risk by 13 percent.

What’s interesting though, is how a sense of control interacts with education level. Feeling in control had a protective effect on the health consequences of lower education—those with stronger control beliefs rated their own health better and, notably, smoked less than those who felt less in control. However, feeling in control didn’t seem to help much at higher education levels.

Implications: “It is likely that perceived control involves a variety of factors, ranging from motivation to beliefs or cognitions, social and behavioral histories of successes and failures, different types of relationships with others, and affective tone,” the study reads. “Some elements of perceived control may vary with changes in external situations, but many may be more dispositional.” There is some evidence, they say, that people can change their sense of control, but a lot of it is just personality, it seems.

The researchers suggest that feeling in control of your life is a type of “resilience process.” It makes sense that if, not only are your circumstances undesirable but you don’t feel like you can do anything to change them, that could wear on a person over time. And feeling in control instead of powerless could easily affect bad health habits, such as smoking, that we do have some control over.

The study, "Perceived Control Reduces Mortality Risk at Low, Not High, Education Levels," appeared in Health Psychology.