"Purpose in life has been robustly associated with health in previous studies," says postdoctoral fellow Yoona Kang, lead author of the study, "but the mechanism through which life purpose may promote healthy living has been unclear."
For this study, published in Health Psychology, Kang and her co-authors chose to test out a theory: that making health decisions might take less effort for those with higher sense of purpose in life. According to Kang, health decisions, even those as simple and mundane as choosing between the elevator and the stairs, involve some amount of decisional conflict. But what if some people experience less conflict than others when considering these options, perhaps because they have a stronger guiding purpose that helps resolve the conflicts?
To test this idea, the researchers recruited sedentary people who needed to exercise more. (To be selected for the study, participants had to be overweight or obese and had to have engaged in fewer than 200 minutes of physical activity in the seven days prior to the screening.) Participants completed a survey about their life purpose by indicating the degree to which they agreed or disagreed with statements like "I have a sense of direction and purpose in my life" or "I don't have a good sense of what it is I'm trying to accomplish in life." Next, they were shown health messages promoting physical activity. Their responses to the messages were monitored by an fMRI scanner, focusing on brain regions that tend to be active when people aren't sure what to choose or when they feel conflicted.
Those participants who reported a stronger sense of life purpose were more likely to agree with the health messages and to have less activity in brain regions associated with conflict-processing. In fact, the researchers were able to predict how likely it was that a person would agree with health messages based on the degree of brain activity in these regions.
"We conduct studies both to understand how different kinds of health messaging can help transform people's behaviors and why some people might be more susceptible than others," says Emily Falk, director of the Communication Neuroscience Lab. "This study does a nice job starting to unpack reasons why people who have a higher sense of purpose in life might be more able to take advantage of this messaging when they encounter it."
Building on this study, Kang's next research project will examine the interactions between genes, brain activity, and life purpose. Funded by the Mind and Life PEACE Grant, she will test whether having certain genes may predict greater synchronization between neural regions associated with reward sensitivity and social sensitivity, and whether activity in these neural regions may, in turn, predict the strength of life purpose.