Smokers’ Elevated Rates of Delay Discounting are Independent of Differences in Primary Personality Dimensions

Abstract

Although smokers have higher rates of delay discounting, the extent to which this depends on smoking habit and nicotine use is unclear. Because personality factors are correlated with both delay discounting and smoking, we assessed the extent to which the effect size for smoking and delay discounting was attenuated by using the primary dimensions of personality in Eysenck’s system – extraversion, neuroticism, and psychoticism – as covariates. Smokers (n = 367) and non-smokers (n = 421) completed the Eysenck Personality Questionnaire-Revised (EPQ-R) and the Monetary Choice Questionnaire (MCQ) to measure delay discounting. Smokers had higher rates of delay discounting (d =.315). Although extraversion and psychoticism scores were higher for smokers than non-smokers, and were positively correlated with delay discounting, the effect size for smokers decreased only marginally when personality variables were used as covariates (d =.295). A stepwise regression analysis identified 7 EPQ-R items that best predicted delay discounting (R =.281); controlling for a subscale based on these items only reduced the effect size to d =.252, and among the smokers, nicotine dependence remained a significant predictor of delay discounting. Overall results indicate that smokers’ elevated delay discounting is independent of primary personality dimensions, and although correlational, are most consistent with the view that smoking habit and nicotine dependence are causally linked to changes in impulsive decision making.