Wednesday, Nov. 25, 2009


Are you a lark, an owl or a robin? The answer may affect your grades. Psychologists at Hendrix College in Arkansas studied 89 incoming freshmen and, depending on how they described their sleep preferences, divided them into larks (early to bed, early to rise), owls (late to bed) and robins (somewhere in the middle). At the end of their freshman year, the owl group had an average GPA of 2.84. Larks and robins averaged 3.18. Comparing that performance with the kids' high school records, the researchers found that all the GPAs had slipped (typical for students away from home for the first time) but the owls' had fallen furthest. Part of the problem may be that owls are forced to adhere to larks' morning schedules: they go to bed later but still have to get up for early classes. On average, owls slept 41 min. less per night than the others — enough, perhaps, to make them sleepy in class. Another study, at the University of Pittsburgh, dug deeper into the sleep-and-grades link. Investigators had 56 kids ages 14 to 18 wear a wrist monitor that tracked their sleep-wake cycles for a week. The teens with poor sleep habits did particularly badly at math, while good sleepers did especially well at English. This may provide clues to which parts of the brain are affected the most by sleep — or lack of it.