An Answer To Everything: Why Men Can Sleep Through A Baby Crying And Women Can’t

Is there a reason men can sleep soundly through a baby crying but a woman will be on the alert after just a whimper?

This new research says there is.

The study, carried out by the National Institute of Child Health in the US, has discovered that women's brains are hard-wired to respond to a baby's cry, while men do not seem to react at all.

Brain scans were conducted on 18 men and women. All of them were asked to let their minds wander.

The researchers then played a recording of white noise interrupted with short clips of a baby crying.

The scans showed the women immediately became more alert after hearing the baby's cry, the men, however, did not.

"Determining whether these responses differ between men and women, by age, and by parental status, helps us understand instincts for caring for the very young," study co-author Marc Bornsteinfrom the National Institute of Child Health and Human Development told Medical Daily.

It has long been known that women's bodies respond to the sound of babies after pregnancy.

Frequent breastfeeding is said to help the "letdown reflex" (the reflex that releases milk produced by breasts) become in tune with a particular stimulation.

But until the mother's body gets used to this, sensations like hearing cries, screams or even having certain thoughts can trigger lactation.