A mother carrying her baby to Caracas, Venezuela in 2020 (AFP / Yadira PEREZ)
It is an experience shared by almost all parents: the frustration of a child crying and refusing to go to sleep.
The researchers set out to help them by scientifically determining which of the four commonly used methods turns out to be the most effective in calming a child who is inconsolable for no apparent reason.
According to their study, published Tuesday in the journal Current Biology, walking for five minutes while carrying a baby can work wonders.
But before letting the baby rest in his bed, scientists recommend holding him in your arms for another five to eight minutes.
“I raised four children,” said the study’s lead author, Kumi Kuroda, of the RIKEN Center for Brain Science in Japan. “But even I could not anticipate the key results obtained from this study, until the arrival of the statistics.”
The team of researchers had previously studied a similar mechanism in animals: when babies (dogs, monkeys, etc.) have to be transported, for example to escape a threat, their heart rate tends to drop and they become more docile.
To compare a possible similar reaction in humans, the scientists studied 21 babies between zero and seven months, with their mother.
Four techniques were analyzed: carrying the baby while walking, carrying it seated, placing it on a bed or placing it on a mobile cradle.
When babies were carried while walking, their heart rate dropped within 30 seconds, just like in a rocking crib, but not when they were standing still.
After five minutes, carrying the baby in her arms allowed all the babies to stop crying and almost half of them fell asleep.
But once they rested in their bed, babies tended to wake up within 20 seconds for more than a third of them.
And the way they were deposited – posture or delicacy of movement – had no impact on this effect.
The solution according to scientists: extend your baby’s sleep time before resting him by sitting and holding him next to you for five to eight minutes after walking.
This period roughly corresponds to the duration of the first phase of sleep, then still light, the study notes.
“We need science to understand a child’s behaviors,” concluded Kumi Kuroda, “because they are much more diverse and complex than we thought.”