Given that 80% of adult smokers develop their habit before age 18, researchers are increasingly focusing on the reasons kids start. Their main discovery: Nicotine's proven ability to suppress appetite and speed up metabolism has made it a popular diet tool for girls and women. Studies by the University of Michigan's Monitoring the Future project found that 14-year-old girls are twice as likely to try smoking as boys, primarily because of concerns about weight. Numerous surveys have found that some 30% of teenage girls and adult women cite weight control as the main reason they smoke, far greater than any other justification. "The relationship between concerns about weight and smoking is dramatic," says Dr. Margaret R. Rukstalis, a psychiatrist at the University of Pennsylvania, who specializes in addictive behaviors.
Scientists are also coming to believe that young brains are biologically receptive to nicotine. Based on adult studies, it was long thought that it takes two years to become addicted to nicotine. But a National Institute on Drug Abuse report published in September found that some adolescents can become addicted within days of trying their first cigarette. Girls appear to get hooked faster. The research team, led by Dr. Joseph DiFranza of the University of Massachusetts, said that teenage girls reported symptoms of addiction, such as cigarette cravings and withdrawal pangs, an average of three weeks after starting. Boys took an average of six months to pick up the habit. This happened even if they only smoked two cigarettes a day.
The biggest risk factor for smoking in a kid's life is parents who light up. That makes smoking seem O.K. and cigarettes accessible. But while smoking is in part a learned behavior, some believe there is a biological predisposition. David B. Abrams, director of the Center for Behavioral & Preventive Medicine at Brown University, says that the children of smokers "may be genetically more vulnerable to nicotine addiction."
Finally, there is the belief that kids smoke because they think it's cool. ALA President and CEO John L. Kirkwood blames the rise in teen smoking on targeted ads by tobacco companies and a romantic image of smoking in movies. Worse, the idea that smoking is cool is filtering down. Between 1991 and '96, smoking by 13-year-olds rose 50%, according to the University of Michigan survey. Today, 5.5% of eighth-graders smoke daily. It's the start of a long habit: Once teens start smoking, it takes them an average of 18 years to quit--the best reason to get them before they take that first puff. By Catherine Arnst in New York