How Fatherhood Rewires Mens’ Brains.
Our society has witnessed a shift over the past few generations. The responsibilty of raising children, specifically caring for infants, has traditionally been that of the mother. While there is still significant variation of paternal involvement across different cultures, fathers are becoming more involved in the care-taking of children and infants.
For most of history, it has been accepted that only womens’ brains were designed to bond with, and care for infants. Considering all the physical changes that occur during pregnancy, it isn’t hard to imagine that the brain also changes, equipping mothers with new neuropathways that make her a natural caregiver. Until now, no study has investigated how the father’s brain might change as it is exposed to more and more parental involvement.
A team of researchers led by Ruth Feldman from Bar-Ilan University created a study to investigate the changes that may occur in a father’s brain when exposed to child rearing. The participants were seperated into groups of two first time parenting couples from Israel. One group included biological parents, where the mother was the primary caregiver, and the father was very involved in raising the child. The second group consisted of homosexual fathers, where one of the fathers was the biological parent, and both were equally involved in caring for the child since infancy.
The study participants were tasked with making three video recordings in their homes: one of both parents interacting with the child, one of the child alone, and one of the parents alone. Before and after each recording, oxytocin levels of the parents were recorded by using a saliva sample. Oxytocin has many nicknames, such as the ‘trust hormone’ and the ‘love molecule’. This hormone also acts as a neurotransmitter, and is released during intimate activities like sex, breast feeding, and birth, and plays a significant role in parental bonding.
A week later, the parents watched the videos of themselves interacting with their children, and were given a functional MRI scan to measure brain activity. All participants displayed activation of two distinct but linked areas of the brain, which the researchers coined ‘the parenting network’. One region was the emotional processing network around the amygdala which is involved in reward and motivation. The other region was that of the superior temporal sulcus, the mentalizing network, which activates social understanding and empathy.
The researchers also discovered differences between the parents. Most often, the mothers displayed strong brain activity in the emotional processing networks, but the heterosexual fathers showed stronger activity in the socio-cognitive networks that are usually experience activated. In both cases, the increased activity correlated with oxytocin levels and behavior. According to the researchers, these results suggest that mothers are in fact more naturally disposed to nurturing and protecting their children, possibly as a result of hormone surges during pregnancy and childbirth. Fathers, however, can develop these same qualities through the experience of caring for their children.
Another interesting finding of this study was the difference in brain activity between the heterosexual fathers and the homosexual fathers. The amygdala of the homosexual fathers showed activity similar to the mothers, and the activity of their superior temporal sulcus was similar to the heterosexual fathers. In both sets of fathers, activity linking the two regions increased with time spent caring for their infants.
Taken together, these findings suggest that fathers who spend time caring for their infants can develop brain activity similar to what mothers develop through pregnancy and childbirth.