Circadian typology and temperament and character personality dimensions.

The purpose of the present study is to explore the relationships between circadian typology and Cloninger's model of the seven dimensions of personality, taking into account the possible sex interactions. This model considers four temperament dimensions (viz., HA, harm avoidance; NS, novelty seeking; RD, reward dependence; and PS, persistence) and three character dimensions (viz., SD, self-directedness; C, cooperativeness; and ST, self-transcendence). A sample of 862 university students (500 women), between 18 and 30 (21.94 +/- 2.64) yrs of age completed the short versions of the Temperament and Character Inventory (TCI-56) and the reduced Morningness-Eveningness Questionnaire (rMEQ). Women showed higher values for HA, RD, and C, while men showed higher values for NS. Evening-type subjects had higher NS but lower HA, PS, and SD scores. Moreover, circadian typology modulated the sex differences in HA and NS, and only evening-type men showed a lower HA score and higher NS score. Circadian typology is related to Cloninger's model of Temperament and Character personality dimensions. Future studies should further examine possible implications, regarding both the vulnerability of developing psychopathological disorders and the prognosis of response to different treatments.