It’s no secret that mothers are sensitive to their babies’ cries, even while asleep. Yet a recent sleep study commissioned by Lemsip, the manufacturer of over-the-counter flu and cold remedies sold in the U.K., suggests it’s not just mothers, but all women, who are quickly roused from sleep by the sound of a crying infant. For men, however, a wailing baby is far less likely to penetrate slumber. While car alarms, buzzing flies and strong wind were all able to interrupt men’s sleep, of the broad range of sounds tested during the study, crying babies didn’t even fall in the top 10 noises likely to disturb male slumber.
The study was conducted by researchers at MindLab at the University of Sussex, an independent research consultancy that specializes in measuring “human responses” in “real life conditions.” Researchers recruited volunteers who were then placed in individual “sleep environments.” Participants were outfitted with sensors to monitor brain activity using electroencephalography (EEG). Once they dozed off, researchers began to play the different sounds, measuring participants’ response by analyzing brain waves using EEG.
They found that, generally speaking, women were more easily awoken, and had more trouble falling back to sleep once their slumber had been disrupted. And, while there were noises that seemed to roust both women and men—snoring, car alarms, sirens, and leaky faucets, for example—a few sounds that stopped each sex’s sleep were notably different. Women were more sensitive to the noise of people carousing outside, for example, while men were more likely to be woken up by crickets chirping and ticking clocks. And of course, while women were most sensitive to sobbing babies, the sound seldom managed to wake men, researchers found.
Dr. David Lewis, a neuropsychologist and director of research at MindLab, suggests that evolution may provide some explanations for these differences. As he told the Telegraph:
“These differing sensitivities may represent evolutionary differences that make women sensitive to sounds associated with a potential threat to their children while men are more finely tuned to disturbances posing a possible threat to the whole family.”
Of course, these findings are very general, and likely do not take into account many factors that could contribute to different levels of noise sensitivity—like whether being the father of a brand new baby, or a single parent, makes you more sensitive to those cries, for example. What do you think? How lightly do you sleep? And, if you’re a parent, have you or your partner been more likely to wake at the sound of the baby’s cries?