A good hug is often a cure and relief in tensed times. Now, scientists have analysed what makes the perfect cuddle - just don`t squeeze too tight.

A team from Japan`s Toho University measured the calming effect on infants of hugs of different pressures, and when given by strangers compared to from parents. By monitoring heart rates for the infant and using pressure sensors on the adult`s hand, the researchers assessed the baby`s reaction to just being held, a hug with medium pressure, and what they called a `tight hug.`

According to the results, published in the journal Cell, babies were soothed more by a medium-pressure hug than just being held but the calming effect decreased during a tight hug. 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 said in their paper.

For infants older than 125 days, the calming effect was greater when receiving a hug from a parent than from a female stranger. So, the perfect hug is considered to be medium pressure from a parent, the scientists believe.

The infants are not the only ones who feel the benefits of a comforting hug, the research showed. Parents also exhibited significant signs of calmness while hugging their child.

It is known that a hormone called oxytocin, sometimes known as the love hormone, is released during close physical contact but the researchers said the time period of their hug experiment was too short for this to play a role.