Neuroscientist Dr. Henry Mahncke Describes How Fatherhood Affects The Brain And Body - Exclusive Interview

Any father knows that having children can drastically alter a person's life. Yet few have thought about the physical changes that come along with it — and we're not just talking about a mother's post-pregnancy body. Fathers' brains and bodies are also forever changed once their children enter the world.

You may be wondering how that's even possible. After all, men don't have to give birth, breastfeed a baby, or navigate a new influx of hormones — but you'd probably be surprised to know their hormones do significantly change as soon as they lay eyes on their child.

To figure out exactly how this happens, Health Digest spoke with a specialist: neuroscientist (and father of two) Dr. Henry Mahncke, who received a Ph.D. in Neuroscience from the University of California San Francisco and continues to study fathers' changing brains as CEO of BrainHQ.

In an exclusive interview with Health Digest, Dr. Mahncke described how having a child can completely change a father's brain and body, how having multiple children can affect a father's chemical makeup, and if it's even possible for a man to be diagnosed with postpartum depression or anxiety.

A mother's hormones change with pregnancy, but are a father's hormones affected at all after having a child?

A big difference between how motherhood affects the brain and how fatherhood affects the brain is that a mother's brain begins to change during pregnancy as a direct result of her body's interaction with the developing baby. A father's brain really only begins to change once the baby is born, and the way that a father's brain changes is directly related to how the new father interacts with the baby.

One of the biggest changes that happens is [that] as a new dad spends time with a new baby, caring for the newborn and caring for the mom, he experiences hormonal changes — oxytocin is released, while testosterone goes down and estrogen increases. These hormones cause changes in brain networks and function, which then promote more caring behaviors from the new dad.

How quickly does the male brain change after becoming a parent? How does this compare to a mother's brain?

The first big brain change begins when the father-to-be first gets the "big news!" That news — with its life-changing importance — causes the brain to pump norepinephrine and noradrenaline, the neurochemicals that get produced in the brain when you encounter new things that merit your attention. For most, it's viewed as good news and a positive surprise, causing the brain to pump a lot of dopamine — the chemical the brain produces when it feels rewarded.

These brain chemicals — neuromodulators — improve mood and make the brain more plastic and responsive to change and new learning. That's a good thing because babies bring a lot of change to daily life.

When we talk about brain changes in the mother, who has carried the child in her womb, we tend to focus on the flood of oxytocin — the brain chemical that assists with the attachment of parent and child. As both the new mom and the new dad interact with the new baby, both of their brains change further, adapting as they learn the sound of different cries and what they might mean and the skills required to change a diaper.

One of the ways that caring for a baby changes brains the fastest is the direct, physical contact of caring for the baby: holding, rocking, feeding, and — the most challenging — getting the baby to sleep. New moms who are breastfeeding might spend a bit more time in direct contact with the new baby, but new dads can catch up and give that mom a well-deserved break with extra play time, rocking, and just being together.

Over thousands of hours of child-rearing, that attachment grows progressively as the child becomes an extension of self in the brain of the parent. That same sort of attachment grows over time in the brain of any loving person playing a key role as the child grows and develops.

Does the age a man becomes a father have any effect on how his brain changes?

The brain can and does rewire itself at any age. Older dads aren't at any disadvantage compared to younger dads in adapting their brains for the new learning and the new challenges of fatherhood.

How do these changes affect the rest of a father's body? Does a father's changing brain have any direct influence on the infamous dad bod?

"Dad bod" is a relatively new slang term to describe common changes to the male body at middle age — thirties to fifties — when there is an increase of body fat around the waist. It used to be called a "beer belly," and one of its causes tends to be an increase in alcohol consumption. It is mostly driven by a decrease in exercise coupled with a slowing of metabolism and an increase in calories consumed, especially fast carbs. It seems to me to be a misnomer, because fatherhood often requires increases in physical exertion to keep up with young children.

While a similar condition among women, often called "midlife spread," comes a bit later — [in their] forties and fifties — and is associated with chemical changes due to menopause, I am not aware of any similar hormonal theory behind dad bod.

Can the changes occurring in a father's brain have any significant impact on his child?

The attachment between parent and child is bilateral. Just as a parent incorporates the child into his or her own sense of self and pumps oxytocin when the child is near physically or in one's thoughts, the child does the same. Certainly, the love, attention, and support that flows from an engaged and active dad causes changes in a child.

How often does a father's brain change throughout his child's life?

Everyone's brain is constantly changing based on life experiences. More significant life events tend to correlate to larger brain changes. Raising a child from newborn through the teenage years and into young adulthood certainly involves some major life experiences and events.

These changes are continuous and ongoing, rather than occasional. The question isn't how often does the father's brain change, but how much does it change, as the father himself grows from caring for the physical needs of a newborn to helping an elementary school child learn to read to helping a teenager navigate the stormy ups and downs of their adolescent social life. All kinds of exciting things are happening all the time that are changing the dad's brain. Everything that's happening in your interactions with the child, you know to be important. In a sense, you have your brain turned up on high.

It's a special time for a father to rethink and relive all of the things in his life at a time when the brain is really listening. The father is changing himself very much on the basis of his interactions with the child. It's an enriching period for the brain.

During which stage in a child's life is a father's brain most drastically altered?

The first time the father holds a child in his arms, he feels, smells, sees, and hears the baby that he and the mother-to-be have been anticipating — this beautiful little girl or this precious little boy. What a moment that is! It's incredibly rewarding in the brain. Imagine the chemical lightning that's going off at that time. It's one of the great moments in life.

Does co-sleeping, skin-to-skin contact, or any other specific interactions between a father and child cause direct changes to a father's brain or body?

Physical contact is an incredibly powerful contributor to bonding and to brain plasticity as well. A lot of the brain is devoted to the sense of touch, so being touched and being in skin-to-skin contact drives a lot of brain activity. That physical contact — especially when it is emphasized by the feeling of caring, attachment, and love that come with being a new dad, which release neuromodulators like acetylcholine, dopamine, serotonin, and norepinephrine — can drive big rewiring changes in the brain.

Is there such a thing as a paternal instinct?

Yes. There has always been a natural instinct among fathers to care for a child. Social expectations may differ by culture or epoch, but the instinct to step up to being a dad seems timeless, and it's important from an evolutionary perspective and the survival of the species.

Is it possible for a father to suffer from postpartum depression or postpartum anxiety in the same way as a mother?

Yes. The medical profession now recognizes that postpartum depression can be very real for both mothers and fathers. While the chemical changes in pregnant women are more pronounced, new fathers can also experience chemical changes that impact mood. Some of this may be explained by hormonal shifts and other brain chemical reactions to the change in life circumstances that may drive concerns about sharing with and providing for a new family member. Family members, caregivers, and clinicians should be alert to these mood symptoms and take them seriously.

Does having additional children create any significant changes to a father's brain?

While the novelty of a first child is unique at that point in a father's life, each child is another major event that stimulates its own brain changes while repeating many prior neurological events. In fact, because different kids are different, a father may find his brain unwiring some of the skills and instincts developed for a first child and rewiring new ones appropriate for the next child.

Do the same changes that occur in a father's brain repeat after becoming a grandfather?

I tend to think of grandparenting as a third pass at getting things right in life. The first pass was as a child, and the second pass was as a parent guiding a child. In the third pass, you're a grandparent.

As a grandparent, you are re-analyzing and re-constructing a life experience in your brain to make better sense of it. This is especially true in watching and helping your grandchildren as they explore the world for the first time. You've gathered a lifetime of knowledge, and you are continuously analyzing and weighing things in your brain. Ultimately, the product of that is supposed to be — and you dream it would be — wisdom.

While I've not yet attained grandfather status, nor wisdom, I can say that based on many decades of life experience, fatherhood is about the best thing that ever happened to me.

What has your work at BrainHQ revealed about a father's changing brain?

Our work at BrainHQ is focused on building evidence-based, computerized brain exercises that measure and improve brain performance and health across the brain. The science we have brought into the world is based on the discovery of lifelong brain plasticity by our co-founder, Dr. Mike Merzenich — that is, the ability of the brain to change chemically, physically, and functionally at any age. 

Our AI-driven exercises are constantly using principles of brain plasticity to measure your performance and present you with the right next exercise to drive brain performance and brain health in a positive direction. BrainHQ provides the building blocks of better cognitive function, and it's important that people put those to use in their daily lives, both to enjoy the benefits of a better brain and because so many activities in daily life themselves help further improve brain health. 

I've described why fatherhood is good for the brain. While we have more than 200 published studies attesting to the many benefits of BrainHQ, you don't need a stack of studies to know fatherhood is good for you — just ask any dad.

Head over to the BrainHQ website for more on Dr. Henry Mahncke's work.

This interview was edited for clarity.