The moderating and mediating effects of personality on the association between morningness and well-being

Background: Morningness (morning-eveningness preference or chronotypes) and personality can be both associated with well-being, but few studies have directly compared these two constructs as correlates of well-being. Thus, the first purpose of this study was to test the effects of interactions between stable personality traits (temperaments) and morningness on well-being. Furthermore, personality factors are often composed of both stable biological factors (temperament) and socio-cultural factors (character), and little is known about personality interplay of temperament and character factors with respect to morningness and well-being. The second purpose of this study was therefore to examine the sequential mediating effects of temperament and character factors on the relationship between morningness and well-being. Methods: The Composite Scale of Morningness, the Korean version of the Temperament and Character Inventory-Revised Short Version (TCI-RS), and the Satisfaction with Life Scale were used to measure morningness, personality dimensions, and well-being, respectively, in 287 Korean university students. Moderating and sequentially mediating effects of temperament and character traits were determined using Hayes' PROCESS macro in SPSS after controlling for sex and age. Results: First, novelty-seeking (NS) and persistence (PS) temperaments have demonstrated the moderating effect in the association between morningness and well-being. The positive effects of morningness on life satisfaction increased with lower NS and PS, respectively. However, other temperaments such as harm avoidance (HA) and reward dependence (RD) have not shown the moderation in the relationship between morningness on well-being. Second, HA temperament and self-directedness (SD) character sequentially mediated the relationship between morningness and well-being. The combination of low scores of HA and high scores of SD have shown the positive effect on the relationship between morningness and well-being. Discussion: This study demonstrated that both the interactions between temperaments and morningness, and combination of specific TCI-RS temperament and character traits play important roles in influencing the association between morningness and well-being. The significance of the mature SD character and its implications for well-being are discussed with limitation of the present study.