Mother's Arms

The world can be a scary place, especially if you’re less than a year old.

Thankfully, our mother’s arms are biologically the most comfortable place in the world, which is why babies are so docile when they're held. And every mother knows the joy of a cooing, quiet baby. 

Researchers at the RIKEN Brain Science Institute in Saitama, Japan, studied the effect of a mother’s embrace on an infant and found that a mother’s arms really are the best, most natural place for a crying baby to be.

Studying a Baby’s Response to Being Held

Dr. Kumi Kuroda, a visiting associate professor at RIKEN, was cleaning mouse cages in her laboratory when she noticed something.

“When I picked the pups up at the back skin very softly and swiftly as mouse mothers did, they immediately stopped moving and became compact,” she said in a press release. “They appeared relaxed, but not totally floppy, and kept the limbs flexed. This calming response in mice appeared similar to me to soothing by maternal carrying in human babies.” 

To test the full effect of a mother's embrace on her child, Kuroda and colleagues carefully measured the heart rates of human babies before and after being picked up. They even managed to find small enough instruments to test the tiny mouse pups.

Moms Are Like Xanax for Infants

In both mice and humans, a baby’s heart rate slows immediately and crying subsides when they are picked up. They also stop moving, researchers found, indicating a calming effect.

To scientists, this says that a baby’s proprioception—or sense of body proximity—is tied to its mother, which is why a crying, finicky baby will often move about. This, the researchers said, is a cry for connection with the mother that’s ingrained in many animals long before they are born.

The findings not only demonstrate the importance of the mother-baby relationship, but may also have implications for preventing child abuse by helping parents better understand how a newborn behaves.

“A scientific understanding of this infant response will save parents from misreading the restart of crying as the intention of the infant to control the parents, as some parenting theories—such as the 'cry it out' type of strategy—suggest,” Kuroda said. 

The RIKEN research was published Thursday in the journal Current Biology.

A Date to Remember

Mother’s Day is Sunday, May 12. Don’t forget to thank her for keeping you safe all these years.

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