A team of psychologists from University of Virginia and University of Utah say they can predict your physical health as an adult based on the quality of your friendships when you’re a teen. Even more, their new analysis indicated non-conformist teens had a lower quality of health compared to their more conformity-minded peers once they all became adults.

“Both of these long-term predictive relationships potentially cast a range of adolescent behaviors in a new light,” concluded the authors, who added the intense focus teens place on their “peer relationships may well result from an instinctive recognition that these relationships are linked to well-being.”

Asked if more friends as a teen equated to even better health as an adult, Dr. Joseph P. Allen, co-author and a professor of psychology at UV, told Medical Daily the new study didn’t directly assess the impact of higher numbers.

“We did find predictions from close friendship quality but not from broader measures of popularity, which would suggest that close friendship is the key,” he said.

Loner or Lost in the Crowd?

Past studies have suggested that social isolation may create low-level, chronic stress. While we can handle severe (but temporary) stress satisfactorily, our systems do not manage chronic stress well at all, the authors said. In fact, chronic stress resulting from social isolation is associated with “an array of negative physiological changes, from increased ambulatory blood pressure to impaired immune functioning,” they wrote.

The opposite of social isolation would be allocentric behavior, described by the authors as “acting as a follower more than a leader, being low in assertiveness, and being readily influenced by peers” — essentially, melding with a crowd.

For their study, the researchers posed a simple question: How does allocentricism during the teen years compare to social isolation when measuring future health?

To conduct their investigation, the researchers relied on data from a larger study that tracked teens into adulthood: from age 13 to age 27. Participants included 171 seventh- and eighth-graders (74 males), who were racially, ethnically, and socio-economically diverse.
Between the ages of 13 and 17, participants and their best friends answered questions assessing the degree of trust, communication, and alienation in their relationship. These friends also provided information about how much a participant focused on fitting in with peers. When the teens reached adulthood, the researchers annually assessed their health at ages 25, 26, and 27. Once a year, participants answered questions about their overall health, symptoms of anxiety and depression, body mass index, medical diagnoses, and hospitalizations.

After analyzing all the data they'd collected, what did the researchers discover?

Simply, participants who had high-quality and close friendships — and a strong drive to fit in — racked up better overall health scores at age 27. So, while “autonomy-establishing behavior is clearly of value in modern Western society,” the researchers noted that this form of social isolation linked to stress reactions, probably due to the fact that, over the course of evolution, “separation from the larger human pack was likely to bring grave danger.” What we prize, then, may not be particularly healthy.

Meanwhile, the researchers carry on with their work.

“We are continuing to follow this sample, and are now collecting physiological markers that may account for the relationships-health link we find,” Allen said. “Given the findings that, in adulthood, social isolation is associated with a range of health problems, even including early mortality, I believe it is quite likely the link will endure.”

Source: Allen JP, Uchino BN, Hafen CA. Running With the Pack Teen Peer-Relationship Qualities as Predictors of Adult Physical Health. Psychological Science. 2015.