Students who rely on working at night to improve their grades might want to sleep on that strategy: a new survey in the U.S. says those who never study all night have slightly higher grades than those who do.

 




A survey of 120 students at St. Lawrence University, a small liberal arts college in northern New York, found students who never worked all night had a 3.1 grade point average compared with 2.9 for those who have. Four is the highest GPA on the scale.

 




The study, by assistant professor of psychology Pamela Thacher, is to be included in the January issue of Behavioral Sleep Medicine.

 




“It’s not a big difference, but it’s pretty striking,” Thacher said.





Dr. Howard Weiss, a physician at St. Peter’s Sleep Center in Albany, said the study results make sense.





“Certainly that data is out there showing that short sleep duration absolutely interferes with concentration, interferes with performance on objective testing,” he said.





Some night owls do get good grades, of course, which may be explained by circadian rhythms, Weiss said. Some people have different 24-hour body clocks than others, and may do better depending on class and testing times, Weiss said.