A hug is a form of affection, universal in human communities, in which at least two individuals put their arms around the neck, back, or the waist of each other and holds each other intently.
Physically, hugs relax your muscles and release tension in your neck and shoulders. Mentally, it gives you peace and is like taking a big, deep breath for your well-being.
Scientists from Japan’s Toho University have analyzed what makes the perfect cuddle. Scientists measured the calming impact on infants of hugs of different pressures, and when given by outsiders contrasted with from parents.
By monitoring the infant heart rates and using pressure sensors on the adult’s hand, the researchers assessed the baby’s reaction to being simply held, receiving a hug with medium pressure, and what they called a “tight hug”.
The results, published in the journal Cell, found that babies were soothed more easily by a hug with medium pressure, than they were when they were just being held.
But the calming effect decreased when they were given a “tight” hug.
When it comes to the effects of the different hug givers, unsurprisingly for infants older than 125 days, the calming effect was greater when receiving a hug from a parent than from a female stranger.
Therefore, researchers suggested the perfect cuddle requires medium pressure and should be given by a parent.
The researchers kept the length of the hug to 20 seconds as “it was almost impossible to avoid infant’s bad mood during a one-minute or longer hold or hug”, they shared in their paper.
Turns out we don’t grow out of the benefits of comforting hugs either.
The research also revealed that parents also exhibited significant signs of calmness while hugging their child.
Both parents and infants both showed an increase during a hug in what’s known as the R-R interval (RRI) on an electrocardiogram.
This is the time between a particular waveform that measures electrical activity of the heart and the increased time indicates a slowed heart rate.
“The infants older than four months old showed a high increase ratio of heartbeat intervals during hugging by their parents than by female strangers,” explains first study author Sachine Yoshida, of Toho University, in a release.
“Parents also showed a high increase ratio of heartbeats intervals by hugging their infants. We found that both infants and parents come to relax by hugging.”