Smokers Often Quit for Social Reasons

May 21, 2008 -- The decision to quit smoking is a personal one, but it is strongly influenced by the people around you -- even people you don't know, intriguing new research shows.

In the largest study ever to explore the collective social dynamics of smoking in the U.S., researchers concluded that social influences have played a huge role in the dramatic declines in smoking over the past few decades.

Just as many smokers pick up the habit to fit in with a particular social group, they appear to quit for the same reasons.

And they tend to quit in droves, with whole clusters of people directly and indirectly belonging to the same social networks quitting at the same time, the researchers wrote in the May 22 New England Journal of Medicine.

"The analogy I like to give is that it is like a flock of birds," researcher Nicholas A. Christakis, MD, PhD, of Harvard Medical School tells WebMD.

"An individual bird in a flock doesn't decide to fly to the left or to the right, and in a very fundamental way smoking cessation behavior in humans has been similar to flocking behavior."

Smoking Affects Social Status

Over the last four decades, smoking rates in the U.S. have declined by more than half, with 21% of adults currently identifying themselves as smokers, compared with close to 45% in the mid-1960s, according to the National Center for Health Statistics.

Revelations about the health risks of smoking and efforts to alert the public to these risks are largely responsible for the declines.

But the new research makes it clear that the shift in how smoking and smokers are viewed by society has also been a driving factor.

More than 12,000 people enrolled in the ongoing Framingham Heart Study who were followed for over three decades, from 1971 until 2003, were included in the study.

Christakis and co-researcher James Fowler, PhD, of the University of California, San Diego, were able to identify social networks among the study participants and how those networks changed over time.

Each study participant had an average of 10 other participants that they were directly or indirectly linked to in a single social network.

Not surprisingly, the closer the relationship between contacts, the greater the influence on smoking. When a spouse quit smoking, the other spouse's probability of continuing to smoke decreased by 67%. When a sibling, friend, or close co-worker quit, the chances that a participant would remain a smoker decreased by 25%, 36%, and 34%, respectively.

When the researchers analyzed social networks as a whole, they found that entire groups of people who might not even know each other all quit smoking in a relatively short time.

These networks also become increasingly more polarized with respect to smoking over time.

"If you look back at 1971, smokers and nonsmokers alike were at the centers of social networks," Fowler notes.

But during the '80s and '90s, smoking and smokers became increasingly marginalized, relegating them to what Fowler calls the "periphery of the social network."

"Contrary to what we might have thought in high school, smoking has become a supremely bad strategy for getting popular."