New research on quitting smoking shows that people willing to do it are more likely to give up the habit in groups than alone.

Therefore, one person’s choice to give up smoking often influences friends, family members, or work colleagues to reconsider their unhealthy habit. And this is a good thing knowing what consequences cigarettes have on our health.

There are many people in the U.S. who already quit smoking. According to the Centers for Disease Control and Prevention, in 1965, 42 percent of the population smoked. That number has been falling to nearly 20 percent in the recent years.

The study made by Dr. Nicholas Christakis of Harvard Medical School and James Fowler of the University of California and funded by the U.S. National Institute on Aging followed 12,067 people who participated in the Framingham Heart Study for 32 years, from 1971 until 2003, analyzing them as part of a large network of relatives, co-workers, neighbors, friends and friends of friends. The Framingham study, launched in 1948, has provided the strongest evidence of the links between diet, lifestyle, and heart disease.

Overall, the study found that when a husband or wife give up smoking, there is 67 percent chance that their spouse would quit. When a friend quit, the chances of smoking among their friends fell by 36 percent. Also, quitters influences their brothers or sisters. Therefore, siblings were 25 percent likely to smoke if one of them quit, while friends of someone who gave up the habit was 36 percent less likely to smoke.

“This study tells us that social relationships have a critical impact on health behaviors and decisions, and that people are strongly influenced by those in their social sphere,” said National Institute on Aging director Dr. Richard Hodes, as quoted by Reuters.

The researchers found that education was also a factor in a person’s decision to quit smoking. The higher the educational levels among the contacts, the greater the influence on smoking behavior.

“We are more influenced by the quitting behavior of others if those people are highly educated. To add a further twist, we are also more influenced by others if we ourselves are more educated,” Dr. Christakis said, according to BBC News.

Another interesting finding of the study was that closeness seemed to play an essential role in someone’s decision to quit smoking. Therefore, the better you know the person quitting, the more chances you have to quit yourself.

“Interestingly, geography did not appear to play a role because smoking behaviors spread between contacts living miles (km) apart and in separate households. Rather, the closeness of the relationship in the network was key to the spread of smoking behaviors,” Dr. Christakis said.

Finally yet importantly, the study found that those continuing on their habit were more likely to be marginalized, regardless of their education or income level.

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

Therefore, the study concluded that not only that smoking is bad for your physical health, but it also is bad for your social health, as smokers “are likely to drive friends [who continue to smoke] away,”

The study was published in the May 22 issue of the New England Journal of Medicine.