Tobacco "chippers"--individual differences in tobacco dependence.

This study explores the behavior of tobacco "chippers"--very light smokers who regularly use tobacco without developing dependence. Eighteen chippers (CHs) who averaged a maximum of five cigarettes per day, but who smoked at least 4 days per week, were compared to 29 dependent smokers (DSs). Laboratory data showed that CHs inhale cigarette smoke and are exposed to nicotine. In both experimental and retrospective self-report data, CHs showed no signs of tobacco withdrawal when abstinent. CHs also differed from DSs in their pattern of smoking: their smoking was less linked with mood states. However, the hypothesis that they were "social" smokers was contradicted. CHs also differed on psychosocial variables relevant to a stress-coping model of smoking: they reported less stress, better coping, and more social support, but these differences were small. Although the two groups were demographically similar, smoking behavior differences between CHs and DSs were long-standing: the two groups differed in their responses to initial smoking and in their family histories of smoking and cessation. CHs' smoking behavior challenges classical theories of dependence; further research is needed on the factors that may protect CHs from addiction.