New dads secrete hormone that tightens baby bonds, Israeli study shows

Studies conducted by an Israeli scientist suggest that, like women, new fathers secrete hormones that strengthen their attachment to their infants. Prof. Ruth Feldman, a psychologist and brain scientist at the Gonda Multidisciplinary Brain Research Center at Bar-Ilan University, and adjunct professor at the Child Study Center at Yale University School of Medicine, recently published a series of studies describing the hormonal activity in new fathers that enhances the feeling of fatherhood and their connection to the newborn infants.

Most research until now has sought to scientifically measure the bond of love between mothers and the newborn.

In contrast, in the study led by Prof. Feldman, as part of the doctoral thesis of Ilanit Gordon, and published this month in the journal Hormones and Behavior, researchers studied the levels of oxytocin and prolactin produced in fathers when interacting with their infants.

It has been previously established that mothers secrete oxytocin during pregnancy, and that prolactin increases milk supply in a baby's first months. The current study measured the level of these hormones in the blood and saliva of fathers in the second and sixth months of the newborns' lives.

	Prolactin and oxytocin prove to be present in male parents as well.
	Photo by: Getty Images

Some 43 fathers were documented on video as they played social games with the infants, and games meant to pique the babies' curiosity. They were asked to present the babies with six new toys kept in a basket.

The researchers tracked the connection between the fathers and infants in terms of fathers' glances at the children, their demonstration of affection, the sounds they made, and physical contact, including hugs, kisses, and touching the babies' bodies, hands and feet.

It emerged that fathers with higher levels of prolactin were more likely to play the investigative games meant to arouse curiosity.

At the same time, the higher the level of oxytocin, the more likely the fathers were to establish a strong social connection with the baby. "Hormones such as prolactin and oxytocin have a significant role in establishing a sense of fatherhood during the infant's first growth stages," Feldman says.

Mothering love, fathering curiosity

In an earlier study led by Prof. Feldman, increased levels of oxytocin were found in both mothers and fathers who played with their babies for 15 minutes. Hormone levels were measured in 112 parents - 71 mothers and 41 fathers - from saliva samples taken before and after play.

Findings showed that oxytocin levels rose during play among both mothers and fathers, but that in mothers this happened only if they gave the babies a lot of loving physical contact. In contrast, the hormone level rose in fathers only if they supplied a stimulating touch that encouraged the infant to explore.

An additional study directed by Feldman and published recently examined the levels of oxytocin in infants. It was conducted with 55 parents (36 mothers and 19 fathers ) of infants aged from four to six months. Its findings show that hormone levels after play increased in parents and babies alike.

"In this way, via coordinated interaction, parents shape children's ability to establish close relations, to feel empathy, to understand the feelings and intentions of others, and to trust in the other," Feldman says.