Smoking: Shared Cigarettes

A smoker rarely stays alone. Just as one cigarette can be lit from another, smokers can pass their habit to the people around them.

Studies show that people who fall in love with smokers or maintain friendships with them are more likely to start smoking themselves. The effect can appear as early as school, where a single smoker may fuel nicotine consumption across an entire grade. Smokers also tend to smoke more cigarettes in the company of other smokers than they do alone.

But what makes smoking such a contagious social force? A new study published in the International Journal of Psychology suggests that the trigger is not simply having other smokers nearby. Instead, it may be something that develops between two smokers: an intimate moment in which they inhale, exhale and tap away ash at the same time.

The study raises the possibility that unconscious imitation helps shape smoking behavior. The same social mechanisms may also affect people's readiness to stop, although the article presents these as questions addressed by the research rather than settled conclusions.