Skip to main content

Sense of Purpose Strengthens Immune System

A new study finds that, on a genetic level, all happiness is not created equal.
  • Author:
  • Updated:


Are happy people also healthier people? Researchers who have examined that question on a genetic level report the answer depends upon your definition of “happiness.”

They have found a strong link between living one’s life with a sense of purpose and enjoying a robust immune system. However, shallower forms of happiness such as “simple self-gratification” produce the opposite result, weakening the body’s immune response.

A new study finds these two basic types of happiness—“eudaimonic” and “hedonic”—produce internal changes that are in “stark contrast at the level of molecular physiology.” It has just been published in the Proceedings of the National Academy of Sciences.

Could it be that feeling self-satisfied is inevitably (but often unconsciously) accompanied by the fear that this contentment won’t last?

The research team, led by psychologist Barbara Fredrickson of the University of North Carolina-Chapel Hill and Steven Cole, a professor of medicine at the University of California-Los Angeles, measured the activity of certain key genes that regulate the immune system. They used blood samples of 84 people, all healthy adults recruited in the Durham and Orange County regions of North Carolina.

Participants revealed their level and type of happiness by answering a series of questions. Specifically, they indicated how often in the past week they felt (a) happy, (b) satisfied, (c) that their life had a sense of direction, (d) that they had something to contribute to society, and (e) that they were challenged “to grow and become a better person.” They also answered questions about their health, and whether they suffered from any symptoms of depression.

Not surprisingly, the researchers found considerable overlap between the two types of happiness. Participant surveys revealed they had “similarly strong inverse relationships to symptoms of depression.” However, on a genetic level, they produced “markedly divergent” results.

Strikingly, hedonic happiness was associated with higher levels of the sort of immune-system genetic activity that is typically provoked by extended periods of stress—activity that can increase inflammation and decrease antiviral responses. In contrast, eudaimonic happiness was associated with lower levels of this unwanted genetic activity.

Could it be that feeling self-satisfied is inevitably (but often unconsciously) accompanied by the fear that this contentment won’t last, which provokes a stress response on a genetic level? If so, this research suggests a sense of meaning and purpose fails to produce that same adverse reaction.

The researchers are quick to note that the two types of happiness often share common sources (such as strong social connections) and can reinforce one another. However, “for people in whom one form of well-being outweighs the other, striving predominantly toward meaning may have more favorable effects on health than striving predominantly toward (personal happiness),” they conclude.

They add that these results imply “the potential for an objective approach to moral philosophy rooted in the utility of health, and the basic biology of human nature.” We may feel terrific when our own immediate needs are met. But our genes seem to be telling us that optimal health requires something more: a genuine sense of meaning.