Breakthrough Study: Mothers’ and Fathers’ Brains Much the Same in Parenting

July 26, 2015 by Robert Franklin, Esq, Member, National Board of Directors, National Parents Organization

I’m no scientist. So this post will come mostly from this study that came out a little over a year ago (Proceedings of the National Academy of Sciences, 5/1/14). There’s little I can add to what the authors say, but will attempt to say what I think the findings mean regarding their potential to impact family law. For now though, suffice it to say that the conclusions the authors draw are vital to our understanding of parenting and how parental behavior comes about.

I’ve written before about my understanding of that. Humans, unlike 90% – 95% of mammals, are a bi-parental species. Parenting behavior comes about in all species that care for their young after birth as a result of certain hormones such as oxytocin, prolactin, cortisol and others. Parenting behavior is unlike other adult behavior and poses obvious risks for adults who engage in it. Therefore, some special mechanism must be in place for adults to put their own health and well-being at risk in order to nurture and protect offspring. Those hormones are that special mechanism. Mammals that don’t produce those hormones, like male African lions, don’t parent; those that do, do.

So the fact that both female and male humans care for children necessarily means that both sexes have some form of hormonal makeup that encourages the care of children. For women, those hormones are stimulated by pregnancy and childbirth, but what triggers them in men? It’s likely that exposure to pregnant females may have an effect as well as actual caregiving to an infant.

Whatever the case, little is known about exactly how human brains respond to children and parenting. Paternal brains are particularly understudied. But the study linked to makes several breakthroughs in our understanding.

The authors studied three sets of parents – primary caregiving mothers, secondary caregiving fathers in heterosexual relationships and primary caregiving gay fathers.

We measured parental brain response to infant stimuli using functional MRI, oxytocin, and parenting behavior in three groups of parents (n = 89) raising their firstborn infant: heterosexual primary-caregiving mothers (PC-Mothers), heterosexual secondary-caregiving fathers (SC-Fathers), and primary-caregiving homosexual fathers (PC-Fathers) rearing infants without maternal involvement.

So the researchers only studied oxytocin levels using MR imaging. And because there’s no control group in the study, other datasets were used to compare their findings with non-parental adults.

The results were dramatic. The study offers the best indication to date of what parenting really is, i.e. what brain centers are stimulated and how fathers compare with mothers.

Results revealed that parenting implemented a global “parental caregiving” neural network, mainly consistent across parents, which integrated functioning of two systems: the emotional processing network including subcortical and paralimbic structures associated with vigilance, salience, reward, and motivation, and mentalizing network involving frontopolar-medial-prefrontal and temporo-parietal circuits implicated in social understanding and cognitive empathy. These networks work in concert to imbue infant care with emotional salience, attune with the infant state, and plan adequate parenting.

In other words, both mothers and fathers responded to infants by producing oxytocin (a neuropeptide) that stimulated certain parts of the brain the authors call the “parental caregiving neural network.” The two parts of the brain so stimulated worked together. The first part helps parents be aware of their infant’s needs and the second part allows them to understand those needs and plan how to meet them.

PC-Mothers showed greater activation in emotion processing structures, correlated with oxytocin and parent-infant synchrony, whereas SC-Fathers displayed greater activation in cortical circuits, associated with oxytocin and parenting. PC-Fathers exhibited high amygdala activation similar to PC-Mothers, alongside high activation of superior temporal sulcus (STS) comparable to SC-Fathers, and functional connectivity between amygdala and STS.

So, when there’s a primary caregiving mother and a secondary caregiving father, she tends to be in tune with the infant’s emotional state while he tends to “mentalize” the process of parenting, i.e. grasp the matter cognitively.

But if he’s the primary caregiver, his brain tends to behave like a primary caregiving mother’s, while also retaining the behavior of the secondary caregiver dad.

Among all fathers, time spent in direct childcare was linked with the degree of amygdala-STS connectivity.

That is, the more time a father spends in hands-on childcare, the more his brain chemistry resembles that of a primary maternal caregiver. And the converse is also true; the less time he does so, the more he resembles a secondary caregiver. That also means that fathers’ brains are malleable; they alter to respond to and fit the role he takes on, or that circumstances require him to take on.

Needless to say, these findings have considerable salience for public policy. They demonstrate the bio-chemical basis for parental involvement with children and that male and female response to infants is much the same. They also show that fathers at least can be quite flexible bio-chemically in their response to their offspring. They’re perfectly capable of being the secondary or the primary parent.

Obviously, these results are limited. How, for example, would a woman’s brain respond who cares for a child with whom she was never pregnant? Would hers be similar to a man’s? The next time these researchers conduct such a study, maybe they’ll include lesbian mothers or stepmothers.

I’ll have more to say about this study next time.


National Parents Organization is a Shared Parenting Organization

National Parents Organization is a non-profit that educates the public, families, educators, and legislators about the importance of shared parenting and how it can reduce conflict in children, parents, and extended families. Along with Shared Parenting we advocate for fair Child Support and Alimony Legislation. Want to get involved?  Here’s how:

Together, we can drive home the family, child development, social and national benefits of shared parenting, and fair child support and alimony. Thank you for your activism.

#mothers, #fathers, #hormones, #parenting, #bio-chemistry

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