Male & Female Biological Clocks Are Even More Different Than You Thought

A new study found that women’s biological clocks are actually running faster than men’s — the internal clock that determines when we naturally sleep and wake runs about six minutes faster in women. This does not, thankfully, have anything to do with “all women” being “baby-crazy.”

The finding comes from research conducted at Harvard-affiliated Brigham and Women’s Hospital. NPR reports that 157 people “spent up to eight weeks in a windowless sleep lab in Boston, isolated from all cues about what time it was in the outside world.” Aside from testing how long it took someone to flip out and throw a shoe at one of the scientists, the experiment allowed the subjects to drift into their natural circadian rhythm.

Study author Jeanne Duffy says, “What we found was that the cycle length of the biological clock in women was shorter on average than it was in men. The average difference was about six minutes.” It doesn’t sound like a huge difference, but women’s slightly faster pace may be part of the reason that they’re more likely to suffer from insomnia. Plus, more than one in three women have a daily cycle that is less than 24 hours, which may cause them to naturally wake earlier.

The researchers say this information will help doctors tailor sleep therapies based on sex, and they recommend that people limit their exposure to morning or evening light based on whether their cycle is longer or shorter than 24 hours. Though, the majority of Americans probably just need to focus on getting more sleep to begin with. Slight gender differences definitely aren’t as big a problem as consistently trying to function on only four hours of sleep.

Women’s Circadian Rhythm Beats Faster Than Men’s [NPR]
BWH Sleep Researchers Find Sex Difference in the Pace of the Brain’s Circadian Clock [Health Canal]