The present study extends the previous research on the social influences on quitting by investigating inconsistencies between different types of social norms and their main and moderating effects on quitting intentions. The theory of planned behaviour (TPB) served as the theoretical framework. Social influences were operationalised by subjective quitting norm (significant others' expectations that one should quit), descriptive quitting norm (significant others' quitting behaviour), and descriptive smoking norm (partner's smoking). Because gender differences had previously been reported, norm effects were also analysed with respect to gender. A total of 168 smokers who had a partner (47% men, mean age M = 34, SD = 16) completed measures of TPB variables (including subjective quitting norm), descriptive quitting norm, descriptive smoking norm, and smoking behaviour. Subjective and descriptive quitting norms were more inconsistent in women than in men. The descriptive quitting norm enhanced the TPB prediction of intention by 5%. A three-way interaction accounted for an additional 3% of the variance and revealed both that subjective and descriptive quitting norms interacted in their prediction and that gender moderated this effect: the subjective quitting norm correlated positively to quitting intention only in women with a strong descriptive quitting norm. All analyses were controlled for number of cigarettes per day. These findings confirmed that it is important to distinguish subjective and descriptive norms and that differences exist in how these norms motivate women and men to quit smoking. Consistent quitting norms such as quitting of significant others in combination with their expectations that one should quit appear to be less common but more important in women to form a corresponding intention.
Smoking is the largest single cause of preventable death and disease in the world (WHO Report on the Global Tobacco Epidemic, 2008). Given increasing efforts to ban smoking, many smokers perceive a social pressure to quit (Royce, Corbett, Sorensen, & Ockene, 1997) and this pressure is associated with quitting intentions (van den Putte, Yzer, & Brunsting, 2005) and changes in smoking behaviour (West et al., 2001 and Westmaas et al., 2002). At the same time, many smokers have a partner who smokes (McGee & Williams, 2006), which hinders their chances of quitting (Bjornson et al., 1995, Chandola et al., 2004, Homish and Leonard, 2005 and Manchon Walsh et al., 2007). By contrast, the quitting of one's partner increases the chances of personal quitting (Coppotelli & Orleans, 1985). Even though the social pressure to quit appears to be stronger in female than in male smokers (Royce et al., 1997), it appears only to increase the chances of quitting in male smokers (Westmaas et al., 2002). In addition, female smokers appear to be more likely than male smokers to have a partner who smokes (Homish and Leonard, 2005 and Manchon Walsh et al., 2007), which hinders their chances of quitting (Bjornson et al., 1995, Homish and Leonard, 2005 and Manchon Walsh et al., 2007); however, female smokers seem to have increased chances of quitting when their partner quits (Coppotelli & Orleans, 1985). These different social influences demonstrate how norms are communicated either by the expectations of others prescribing an approved behaviour (i.e., social pressure or subjective norm) or by the behaviour of others indicating an approved behaviour (i.e., descriptive norm). Furthermore, these norms can be inconsistent (e.g., approving of quitting and smoking). To extend these findings further, the present study examines subjective and descriptive norms within the theory of planned behaviour (TPB), taking gender differences into consideration. Specifically, we tested any inconsistencies between the norms, and main and moderating effects of each in the prediction of quitting intention. In doing so, we tested whether the effects differed by gender.
