Chronotype and circadian preference variations between younger and older adolescent cohorts

Adolescence is a critical transitional phase characterized by significant physiological and behavioral changes. This study investigated the differences in daily behaviors and preferences between relatively younger adolescents (YAs; mean age 14 ± 01 years) and older adolescents (OAs; mean age 17 ± 01 years) using the Horne and Östberg Morningness-Eveningness Questionnaire (MEQ). A total of 502 adolescents from Lucknow, India, participated in the study. The results showed that most participants were of neither type (52.11 ± 0.34 for YAs and 50.57 ± 0.31 for OAs), followed by morning and evening types. YAs preferred earlier bedtimes (2100–2214 h) and had longer sleep durations than OAs, who had delayed sleep onset (2215–0044 h). Wake times were similar in both groups, likely due to their social obligations. YAs experienced fatigue and sleepiness earlier in the evening and preferred mentally and physically demanding tasks in the morning. In contrast, OAs preferred morning hours for mental tasks and evening hours for physical tasks. A shift towards eveningness was observed in OAs. Factors influencing these differences include pubertal changes, parental guidance, school schedules, cultural contexts and home environments. This study highlights the importance of understanding sleep patterns and task performance in adolescents during this transitional stage. These findings can help us understand circadian preferences during developmental trajectories. This information can also be used to improve age-based sleep hygiene, academic routines, and emotional development in adolescents, considering variations in lifestyle and circadian preferences within this age group.