Morningness-eveningness and personality characteristics of young healthy adults

We aim to explore for the first time the relationships between circadian typology, the personality dimensions of Cloninger's biological model and Zuckerman's sensation seeking model in healthy adults. A sample of 700 young healthy adults (324 men) aged between 18 and 32 yrs completed the reduced Morningness-Eveningness Questionnaire (rMEQ), the short version of the Temperament and Character Inventory and the Sensation Seeking Scale-Form V. Morning-type subjects showed higher scores than the evening- and neither-type in persistence, while evening-type scored higher than morning-type in novelty seeking. A significant interaction in harm avoidance showed that evening- and neither-type men scored lower than women. Evening-type scored higher than morning-type in experience seeking, disinhibition, and Sensation Seeking Total Score (SSS-V), and higher than neither-type in disinhibition and SSS-V. A significant interaction in SSS-V showed that only evening-type men scored higher than women. Regression analyses revealed that rMEQ scores are significantly related to the temperament dimensions novelty seeking and persistence, and to the SSS-V and the disinhibition dimension. Our results, together with the known associations between Cloninger's model and Zuckerman's sensation seeking with diverse health problems, emphasize an evening-type personality profile more vulnerable to the development of symptomatology and mental disorders (especially in men).