Fathers’ brains change when they are the primary caregiver

Gay fathers develop a pattern of brain activity that mirrors both that of new mothers and heterosexual fathers when they are lead caregivers

A new study has found that fathers’ brains are highly malleable and adapt to the level of responsibility they carry for the care of their infants.

In traditional heterosexual partnerships where the mother is primary caregiver, mothers and fathers show similar but distinct patterns of brain activity in response to their child. According to recent findings, gay fathers who take the lead role in caring for their baby show brain activity that combines both these patterns in an integrated way. For all fathers, the more time spent alone with their child, the stronger the synchrony between the different areas of the brain involved in parental care.

According to Ruth Feldman, researcher at Bar-Ilan University in Israel and lead author of the study, the results indicate that by spending time taking care of their children, fathers can foster very similar bonds with them as mothers traditionally have. "Pregnancy, childbirth and lactation are very powerful primers in women to worry about their child's survival. Fathers have the capacity to do it as well as mothers, but they need daily caregiving activities to ignite that mothering network," Feldman told HealthDay.

The study, published online by the Proceedings of the National Academy of Sciences, set out to investigate the neural circuits involved in parental caregiving. Feldman and her colleagues studied 89 first-time parents who all fell into one of three groups: Heterosexual primary-caregiving mothers, heterosexual fathers in a supporting parental role, and primary-caregiving homosexual fathers who were raising their children without the involvement of a woman. The researchers measured the neural activity of the mums and dads whilst they were being shown videos of themselves interacting with their children. The results led to the identification of a ‘parental caregiving’ neural network that is active in both men and women and consists of two integrated systems: An emotional processing circuit involving the amygdala, and a ‘mentalising’ circuit associated with social understanding and cognitive empathy. One of the functions of the emotional circuit is to regulate a parent’s vigilance and awareness of the child’s safety, whereas the ‘mentalising’ circuit helps parents read their infant’s signals.

Although maternal and paternal care were found to have a common neural basis, there were distinctions between the female primary caregivers and the fathers in a secondary child-caring role. The mothers in the study showed more activity in the emotional circuit, whereas the heterosexual fathers exhibited a greater response in the cognitive circuit. In the group of gay fathers, both circuits were active and showed a high level of connectivity. There was no difference in masculinity and femininity between the straight and gay men in the study, thus ruling out any effect those traits might have had on the parental response. In addition, the more time the straight men spent alone with their children, the greater the connectivity between the two relevant regions of the brain.

“Fathers should engage in child-care activity because this is their pathway to brain changes and attachment,” Feldman told Bloomberg. “When mothers are around, fathers’ amygdala can rest and mothers do the worrying. When mothers are not around, fathers’ brains need to assume this function.”

As well as encouraging flexibility in parenting roles, the results of the study could have implications for the global debate on same-sex adoption.