Bite the Stress Away? Nail Biting and Smoking Predict Maladaptive Stress Coping Strategies

Psychological correlates of adult nail biting have received little empirical attention so far, despite its high prevalence and negative associations with physical and mental health. One possible correlate of nail biting is arousal modulation, which has also been linked to smoking (i.e., another oral behavior). Here, we link nail biting to an adaptive (i.e., Task-oriented) and two maladaptive stress-coping strategies (i.e., Emotion-oriented, Avoidance-oriented) as well as smoking while controlling for personality traits and socio-demographic characteristics. In all, 838 German-speaking adults (M-age = 32.02, SD = 13.48; 431 women) completed measures of stress coping (CISS-SF), the Big Five personality traits (Mini-IPIP), and indicated nail biting and smoking behavior. In three theory-guided, hierarchical linear regressions we predicted each stress coping strategy by nail biting and smoking while controlling for personality and socio-demographic characteristics. Oral behaviors had differential effects on maladaptive stress coping strategies: The interaction between nail biting and smoking predicted Emotion-oriented coping, while smoking predicted Avoidance-oriented coping. Both behaviors were unrelated to adaptive, Task-oriented coping. In sum, our results show that nail biting and smoking are important predictors of maladaptive but not adaptive coping strategies, even when controlling for confounders.