An Actigraphic Validation Study of Seven Morningness-Eveningness Inventories

Morningness-eveningness refers to the preference people have regarding the time they like to rise, conduct activities, and go to bed. People denoted as morning types (larks) like to rise early in the morning and go to bed early, while evening types (owls) prefer to sleep until later in the day and stay up until later at night. Various self-report instruments that measure morningness-eveningness have been developed. The aim of this study was to validate seven different self-report measures on morningness-eveningness using actigraphic data. One hundred and sixty-six students (mean age 21.4 years, range 19-30) were recruited from the University of Bergen and Bergen University College. The participants completed the self-report measures and wore an actigraph for seven days. The results showed that all self-report measures were in concordance with actigraphy-measured bed times, rise times, and the nadir for physical activity. In addition, some of the instruments were sensitive to differences between morning and evening types in their total sleep time on weekend nights or their stability in the activity curve across days as measured by actigraphy. Both the strengths and weaknesses of the present study are discussed, and proposals for future research are presented. Keywords: