Witnessing two of my sons become fathers has been a uniquely transformative experience. I hoped they would be good parents. I knew they would be good parents. Over these first few months of observing my sons as fathers, the reality is more inspiring than I could have imagined.
Much has been written about parenting as life-changing. Thanks to today’s science and technology, we now know that parenting actually alters our brains in some exciting and important ways.
1. Pregnancy changes the brain. Monumental hormonal changes occur during pregnancy (don’t I know it!). Research by Amsterdam University Medical Center Professor Elseline Hoekzema and colleagues suggests that these hormonal fluctuations actually change the new parent’s brain. Pregnancy leads to specific and enduring alterations in the neural architecture and organization of the brain. The changes are most dramatic in the “default mode network” of the brain, which comprises the brain regions most active during the internally-focused cognitive activities of thinking, remembering, imagining, and thinking about others’ minds, a process researchers call “theory of mind.” Hoekzema and colleagues documented that these observed brain changes are correlated with pregnancy hormones, primarily third-trimester estradiol, and reported that these changes in the brain are associated with maternal-fetal bonding, nesting behavior, physiological responsiveness to infant cues, and quality of mother-infant bonding.
2. A father’s brain changes, too. Changes due to pregnancy may seem straightforward. But what about the non-pregnant caregiver? Neuroscientists have recently documented that fatherhood also results in changes in brain structures. USC Professor Darby Saxbe and doctoral student Magdalena Martinez Barcia at the Instituto de Investigación Sanitaria Gregorio Marañón in Madrid conducted a study of 40 men – 20 in Spain and 20 in California – who were put into an MRI scanner during their partner’s pregnancy and, again, when their baby was six months old. They compared the brains of these new fathers to 17 men without children. In both the US and Spanish samples, fathers’ brain changes appeared in regions of the cortex that contribute to visual processing, attention, and empathy toward the baby – evidence of behavior experience shaping brain function.
3. Time spent with baby matters – for baby and father. Over the past fifty years, the time fathers spend engaging in child care has tripled in the United States. In countries that provide support for, and even encourage, parental leave for fathers – such as Germany, Spain, Sweden, and Iceland – fathers spend even more time caring for their children. A substantial body of research indicates that children with engaged fathers perform higher on various outcomes, including physical health and cognitive performance. The data now also suggest that father engagement has positive benefits on the father’s brain health and development as well.
4. Paid parental leave matters. The first 1000 days of a person’s life – from conception to two years – is uniquely foundational for brain, body, metabolism, and immune system development. For this reason, many organizations, including UNICEF and the nonprofit organization 1,000 Days, advocate fiercely for healthier and more equitable conditions that support caregivers and their children during this phase of life. The data are clear: family policies that help parents are beneficial for children and parents alike. In countries with more generous paternity leaves, fathers can spend more time with children. Saxbe and Martinez Barcia’s research indicates that when fathers have more time, they show pronounced changes in brain regions that support goal-directed attention, which may help them attune to their infants’ cues. As I noted in a previous Five on Friday, paid parental leave policies benefit mothers, fathers, and infants. It leaves me speechless that the United States is the only high-income country in the world with no national paid parental leave policy.
5. Extrapolating to other relationships. The data on brain changes that occur in the context of parenting are provocative. Connecting hormonal changes of pregnancy to brain changes speaks to a robust biological process. The additional data that behavioral experience, in and of itself, can impact our biochemistry, brain architecture and circuitry has far-reaching implications. If spending time with babies can alter a parent’s brain – whether or not they carried the pregnancy – we have every reason to believe that other intimate and emotionally significant relationships can similarly shape our brains. These data are a clarion call for all of us to consider how we engage socially with others and how our social relationships impact our brains in ways that affect our emotional and psychological health.
From inception, babies alter the brains of their parents – forever. Babies help parents develop empathy and perspective. Advances in neuroscience help us understand the underpinnings of this intimate brain-behavior choreography that has unfolded billions of times over the millennia. What a gift to witness it firsthand.
