Morningness/eveningness and school performance among Spanish adolescents: Further evidence

Adolescents shift their time of day preferences from morning to evening during puberty when school schedule becomes earlier. Given that a better performance is obtained when individuals are tested at times that are in synchrony with their chronotype, and optimal sleep duration is positively associated with academic performance, evening-types may obtain worse school performance because of both morning school schedule and a decrease of total sleep time. A group of 1133 adolescents (aged 12–16) participated in this study. School performance was evaluated using subjective level of achievement and self-reported grades measures. Controlling for total sleep time, more evening oriented young adolescents (12–14 years) performed significantly worse in school achievement. Girls among 15–16 years performed significantly better than boys. These results have important implications for intervention and prevention programs during school years.