Wisconsin researchers have found a surprisingly wide array of reasons why people smoke cigarettes, from being around others who do it to stress relief.

The study by University of Wisconsin researchers, known as the Wisconsin Inventory of Smoking Dependence Motives, also reveals which type of smoker is most likely to relapse, the school said Friday.

Previous measures concentrated primarily on physical dependence, including questions about number of cigarettes smoked, smoking upon waking and smoking when ill.

The inventory, though, evaluated smoker motivation in 13 areas, including emotional attachment to smoking, response to other smokers, smoking to relieve stress, smoking for mental stimulation and smoking automatically.

Novice smokers seemed to be more influenced by environment and sensation. Their motivations to smoke included being in a smoking environment, visual and olfactory cues that encourage someone to smoke, and the taste and sensation of smoking.

Experienced smokers were more influenced by cravings, automatic smoking, the need to smoke even when knowing the negative health effects, the use of smoking to enhance mental activity, and emotional attachment to smoking.

The inventory also found that motives most connected to smoking relapse were automatic smoking, smoking to enhance mental activity, smoking to alleviate distress, and being in a smoking environment.