PSYCHOMETRIC COMPARISON OF 2 CIRCADIAN-RHYTHM QUESTIONNAIRES AND THEIR RELATIONSHIP WITH PERSONALITY

Two questionnaires for the measurement of individual differences in circadian phase position (morningness-eveningness) were psychometrically evaluated and compared: the widely used Morningness-Eveningness Questionnaire (MEQ) by Horne and Östberg (International Journal of Chronobiology, 4, 97-110, 1976) and the Marburger questionnaire by Moog (Night and shift work: biological and social aspects. Oxford: Pergamon Press, 1981). Further instruments given to the sample (113 undergraduate students) were the EPI and a 2-week sleep/waking diary. In addition, two groups of extreme morning and evening types measured their own oral temperature throughout several days. Both circadian rhythm questionnaires proved reliable and valid (with respect to sleep/waking behaviour and oral temperature), although some deficiences were found for the MEQ with regard to its multidimensionality, skewness of distributions and a negative correlation with neuroticism. In line with previous research, a weak negative relationship of morningness-eveningness with extraversion was observed for both questionnaires. Impulsivity, rather than sociability, seemed to be the component responsible for this association. Effects of sex and age were only partially in line with previous findings. © 1991.