Study Examines Teen Sleep Habits

A study, reported recently in CurrentBiology, examined why adolescents go tobed later. Researchers in Germany asked25,000 individuals (from 8 to 90 years ofage) about their sleep and wake times.Based on the participants'responses, theresearchers mapped their "chronotypes"(an individual's endogenous or natural circadianclock "synchronises"or alignmentsto the 24-hour day).

The results of the study indicated thatchildren are early chronotypes and becomeprogressively later during development,reaching a maximum latenessaround age 20, when they become earlieragain. A comparison of men and womenshowed that women reached their maximumlateness earlier (19.5, comparedwith 20.9 years in men). The results furthersuggested that women mature fasterthan men.