Figure 3
Morningness-Eveningness Questionnaire (chronotype) scores in male and female school children of different ages. Filled bars, boys; open bars, girls. Scores indicate: range 16 to 30, definitely evening-type; 31 to41, moderately evening-type; 42 to 58, neither or intermediate-type; 59 to 69, moderately morning-type; and 70 to 86, definitely morning-type.