Sleep data are gathered prior to administration of the well-known p-beauty contest game. Additionally, using a validated morningness-eveningness preference measure, morning-type and evening-type subjects are identified and randomly matched or mismatched into morning or evening experiment sessions. This design allows examination of the effects of voluntary sleep restriction and optimal/suboptima...

STUDY OBJECTIVE The present study aimed to analyze season of birth effects on preferred sleep-wake cycle timing as assessed by Morningness-Eveningness Questionnaire (MEQ). PARTICIPANTS AND MEASUREMENTS The MEQ was administered to a sample of 5,720 university students (3,851 Italians and 1,869 Spaniards; 3,877 female and 1,843 male; mean age 22.23 +/- 2.98 years). RESULTS Females preferred t...

Circadian arousal impacts both physiological and intellectual functioning in humans and has been shown to vary significantly over the lifespan. Normative data indicate that children (ages 7 to 12 years) tend to have morning peaks in arousal, but that adolescents shift to eveningness. This evening preference continues through young adulthood and then shifts back to morningness late in life. Whil...

Many teenagers go to bed and wake up significantly later than younger children, a developmental progression thought to reflect adolescent psychosocial processes. To determine whether biological processes may underlie a delay of phase preference in adolescents, 183 sixth-grade boys and 275 sixth-grade girls completed questionnaires for morningness/eveningness (M/E) and pubertal status. School en...

The creation and adaptation of scales or inventories assessing specific circadian typologies has been a predominant focus within the field of chronopsychology. The present study addressed the psychometric properties of two scales of morningness-eveningness: the Morningness Composite Scale (CS; Smith, Reilly, & Midkiff, 1989) and the Early/Late Preferences Scale (PS; Smith, Folkard, Schmieder, P...

Abstract Introduction Chronotype refers to one’s inclination earlier or later sleeping times. Late chronotype has been linked increased diabetes risk, which may be mediated through adherence unhealthy lifestyle. This study aimed evaluate the interplay among chronotype, lifestyle factors, and risk. Methods In 2009, 63,594 diabetes-free women (mean age=54 yrs) from Nurses’ Health Study II self-re...