Oxytocin has been called "the love hormone" because levels of it rise in women during childbirth and breast-feeding, and it is thought to facilitate bonding. It is present in men, too, and everything from eye contact to orgasm can increase its amount.
But does the hormone stimulate bonding in new fathers as it does in new mothers? A new study in the journal Biological Psychiatry, the first to look at what its authors describe as “the transition to fatherhood,” suggests that it does. And it also suggests a biological basis for the fact that men and women so often relate differently to infant and toddlers, with women more often cooing and cuddling and men tickling and tossing.
First, Israeli researchers took blood samples from 80 couples, all first-time parents, when their children were 6 weeks, and then 6 months, old. Oxytocin levels at 6 weeks, they found, were just as high in new fathers as they were in new mothers (partners appear to “match” each other in the production of the hormone), and the levels rose over the next four and a half months.
The researchers also observed the couples as they interacted with their infants, noting how often each parent did things like gazing at the child, talking “mommy-ese” to him or her, playing with them and otherwise stimulating love and learning. Women with the highest levels of oxytocin were most likely to demonstrate what the journal article calls “affectionate parenting behaviors” while men with the highest levels were most likely to demonstrate “stimulatory parenting behaviors.”Source