The data shows being a dad shrinks your brain, but the cognitive science around fatherhood is patchy at best.
There is little research going on into the inside of fathers’ heads, but understanding it is vital to helping men be good parents. To find out more, we spoke to author Chelsea Conaboy, who has literally written a book about the brain and parenthood.
It’s frustrating, but it is changing. There’s some great work that’s been published synthesizing what researchers have learned from other mammals and what we know so far in human fathers and other non-gestational parents. Generally, the broad themes we see in the research on mothers hold true in fathers: Fathers can experience significant hormonal changes in the transition to fatherhood, including testosterone, oxytocin and prolactin. It’s thought that those changes essentially prime a father’s brain for exposure to their baby’s powerful stimuli. And direct caregiving—exposure to those stimuli and experience responding to them—shapes the paternal brain over time, as it does the maternal brain. The pathway to these adaptations and the exact mechanisms through which they occur are different for gestational and non-gestational parents, but the outcomes may be similar.
There’s more neuroscience of the paternal brain coming. And, in fact, a significant study was published very recently. A group of researchers in Spain and the United States, led by Magdalena Martínez-García, looked at the brains of men before or during their partners’ pregnancy and again some months into the postpartum period and found structural changes in cortical regions of the brain, within the visual network and the default mode network, thought to be involved in understanding and responding to another person’s mental state and emotions. Specifically, they found volume losses in those regions. The losses were subtler than those researchers found in a similar study in mothers, but they were still significant. Importantly—just as in mothers—those volume losses seem to be the result of a fine-tuning of the brain, an adaptive process not a loss of function.
One thing that’s important to note is that there is a lot of variability in human fathering, moreso than in human mothering. Studies of the paternal brain need to take into account how much time a father actually spends with a baby, which is determined by all sorts of factors, including cultural norms, personal preference, and social policies, such as whether they have parental leave that allows them to be with their newborn. That’s hard to do. There are a lot more questions than answers so far, but I’m excited to see where the science takes us.
My sense is that they are not very aware of changes to their brains at all. New parenthood is a major stage of development, but the parental brain is not part of prenatal education or the cultural conversation about what it means to become a parent. It should be, for all parents.
One obstacle to changing that is how we’ve held on to this old idea of maternal instinct and the belief that women—and women alone—have an innate capacity for caregiving that turns on automatically once they become a mother. It’s a myth, and a harmful one. We’ve really mischaracterized whose biology sets them up to be really capable caregivers, and that’s any person who devotes their energy and attention to the role.
If we were to embrace new parenthood as a major stage of development, I think it would require some big changes for fathers. I talk a lot about how inadequate postpartum care is in the United States, where mothers have one standard six-week postpartum appointment. It’s a wasteland. Many mothers turn to mommy groups and social media forums for support and answers to their many, many questions. Those opportunities are far fewer for men. This is a time of life that has major short- and long-term impacts for fathers’ mental and physical health. They deserve more formalized support, whether that’s a check-in appointment with their primary care doctor if they need it, or parenting support groups that are more welcoming and accessible to fathers.
Fathers should have access to paid leave, to give them real time and experience caring for their babies, and we need policies and practices that encourage men to use that leave when it is available to them. Again, in the United States, we’ve got a very long way to go on this. But the research suggests that a father’s time with a newborn matters—not only for that newborn’s wellbeing or for the mother’s recovery, but also for the father’s own development. Two of the researchers on the study I mentioned above, Darby Saxbe and Sofia Cardenas, wrote in an opinion piece in the New York Times last year that “fathers are made, not born: Time with infants is a key ingredient in building the fathering brain.” Social policies and workplace practices need to take that into account.
Lastly, I hope this science can start to change how we talk to one another about our individual experiences of new parenthood, to make those conversations more honest. I think that’s one way it can do the most good.