GENDER DIFFERENCES IN MORNINGNESS–EVENINGNESS PREFERENCE

TLDR

Morningness–eveningness preference is the individual difference that most clearly explains variations in the rhythmic expression of biological or behavioral patterns. The study aimed to analyze gender differences in morningness–eveningness preference using the Horne and Ostberg questionnaire in a large university student sample (N = 2,135, age 18–30 yr). The authors administered the Morningness–Eveningness Questionnaire to 2,135 students, found a normal distribution of scores, and identified three underlying factors—time of greatest efficiency, sleep timing, and awakening inertia—through factor analysis. Men scored significantly lower (more eveningness) than women (p < 0.0001), with gender differences mainly driven by items in factors I and II, supporting recent circadian regulation models.

Abstract

Morningness-eveningness preference (morning-, intermediate-, evening-type) or circadian typology is the individual difference that most clearly explains the variations in the rhythmic expression of biological or behavioral patterns. The aim of this study was to analyze gender difference in morningness-eveningness preference using the Horne and Ostberg questionnaire in the largest university student population selected so far (N = 2135), with an age range 18-30 yr. Morningness-eveningness questionnaire (MEQ) score distribution closely correlated to the normal curve (range 17-78, mean = 48.25; SD = 10.11), with 338 (15.84%) morning-types, 1273 (59.62%) intermediate-types, and 524 (24.54%) evening-types. The men and women differed significantly in their mean scores (p < 0.0001) and distribution per circadian typology (p < 0.00001), with the men presenting a more pronounced eveningness preference. Three factors were identified by factor analysis: time of greatest efficiency (I), sleep time/sleep phase (II), awakening time/sleep inertia (III). The MEQ items sensitive to gender differences were essentially those included in factor I and factor II. The results are discussed in relation to recent models of circadian regulation of the sleep-wake cycle.