Researchers found that people’s chronotypes vary by as much as ten hours, reports Live Science. 

The researchers found that the overall distribution of sleep types formed a fairly predictable bell curve: 50 percent of the population had sleep midpoints fall between 2:24 a.m. and 4:15 a.m., while 25 percent of the sample showed sleep midpointsearlier than that windowand 25 percent showed midpoints after that window.

As many might expect, later sleep chronotypes were most common among teenagers, peaking in17-to 19-year-olds, who had an average chronotype, or midpoint of sleep, of 4:30 a.m. For comparison, the average midpoint of sleep in 60-year-olds was 3 a.m.

Read the rest at