An Israeli study by neuroscientist Ruth Feldman and her team, published in the journal Biological Psychiatry, shows that premature babies who are cuddled, sleep better, have greater affective attention, steadier breathing, and more regular heart rates. Every mammal has to be cuddled and in close proximity with its mother in the first days and weeks of life, as this brings the ventral vagal system online which is the foundation for self regulation. As well, oxytocin increases in both mothers and babies during cuddle sessions which enhances the bond between them.

Feldman and her team examined premature babies at two different hospitals in 1996. Preemies at one hospital received an hour of kangaroo care (the practice of cuddling skin-to-skin) by their mother for two weeks. Babies at the other hospital received none. The study was repeated in 1998 with another two hospitals.

The children were followed-up with heath assessments at the ages of three months, six months, one year, two years, five years, and 10 years old. In this decade-long study, it was shown that providing maternal-newborn skin-to-skin contact to premature infants in the neonatal period improves children’s functioning ten years later. The children at age 10 showed better stress management, as determined by lower levels of the stress hormone cortisol when they were faced with an anxiety-producing situation. In other words, they were better able to self regulate.