Women obviously go through many changes to their bodies and their minds when they become mothers. But what about fathers? Although moms have been studied extensively, few people have paid any attention to what happens to men when they become dads. Do they go through any physical changes at all? Do they also experience hormone surges and shrinking brains like women do (yes mom and dads, your brains got smaller). Do they also suffer from depression and anxiety? Dr. Darby Saxbe has dedicated her career to studying fathers, and in her new book, Dad Brain, the New Science of Fatherhood, she reveals things about fathers that are as surprising as they are dramatic, discoveries which could have enormous impact on how society views dear old dads, and their role in raising children.
Phil Stieg
Women obviously go through many changes in their bodies during pregnancy, and research has shown that their minds do, too. You probably have heard the term “mommy brain”. But what about fathers? Most studies about parenthood have focused on the mothers. But our guest, Dr. Darby Sacksby, a clinical psychologist and professor, has been studying fathers for 20 years. Today, we’ll get a peek at her soon-to-be-released new book, “Dad Brain: Why Great Fathers Are Made, Not Born”. Dr. Saxbe will reveal some surprising insights about both the neuroscience and psychology of fatherhood.
Darby, thank you for being with us today.
Darby Saxbe
Happy to be here.
Phil Stieg
In reading the promo for your book and reading through a number of your papers, I picked up that this is a passion of personal importance to you. Can you maybe tell us a little bit about how you got into studying the dad’s brain and what role your father played in all of this?
Darby Saxbe
Certainly, yeah. So one theme of my book is that fatherhood is transformative for men. And I was lucky enough to witness some of that transformation in real-time. So when I was a kid, my dad was a pretty typical, somewhat checked-out parent. My mom was doing most of the wrangling of me and my two brothers at home. But when they got divorced, I was about nine, and my parents settled on joint custody. So every other week, we were with my father for a full week. And he was left to his devices to figure out what to do with these three young, unruly children. And he had to cook all our meals. He had to clean them after us. He had to check our homework with us. And over time, he rose to the occasion. And ultimately became a really wonderful father and a very hands-on parent.
He was trained as a surgeon in the ’60s, traditional division of labor. But was the guy that really He kept tabs on me and got me through high school. I knew from that own personal experience that men can really rise to the occasion and adapt to parenthood just as women can. And I became curious to understand what’s happening in the brain and body as fathers learn to take care of young children.
Phil Stieg
When you first started, what were the first questions that you really wanted to ask?
Darby Saxbe
I was interested in how our brains and bodies adapt to transition. I wanted to understand plasticity I thought that fathers would be interesting because they don’t undergo the hormonal events of pregnancy, yet they are still involved in taking care of children. So looking at father’s brains in particular, gives us an opportunity to understand the remodeling of the brain in the absence of biological pregnancy. So my first question was, really, does parenthood change the male brain?
Phil Stieg
And the surprising thing was what?
Darby Saxbe
We were looking at the structure or the volume the brain over time, so from pregnancy to six months postpartum. What we found was that men were losing gray matter volume, which seems like not a great thing until we remember that there’s research showing that in women, there’s also a loss of cortical gray matter volume, and it appears to be adaptive.
We know that the brain prunes and loses volume at important periods of development in early childhood, and then again in adolescents. And longitudinal work on mothers has found that they lose gray matter volume in regions that are important for social cognition. So what we think of as the mentalizing network, which is a series of interconnected structures that help us understand other people’s minds.
What we saw when we looked at the fathers, we found very similar and convergent patterns in our men, which was that they were losing gray matter volume in many of the same regions that had been previously seen in women. So very similar pattern from mothers to fathers. But the father’s patterns were more subtle and more variable, suggesting that there was a role for individual differences in men’s adaptation to parenthood.
Phil Stieg
What neuropsychological changes did you see?
Darby Saxbe
So we compared our prenatal scans to the postpartum scans. I already told you a little bit about the volume loss that we saw, particularly in the cortical mentalizing network regions that had been observed in the mothers. And we linked those changes to men’s mental health and sleep across the transition to parenthood.
First of all, we found that when men were more motivated to participate in caregiving, so when they told us they wanted to take more time off after birth, they were more engaged in the first few months after birth, and they spent more time with the infant, they showed a greater magnitude of volume changes. So it appeared like consistent with the research on mothers, men’s brain remodeling was really tracking with their day-to-day involvement in parenting their new infants.
But we also found a darker side, which was that when the brain changed more in volume from prenatal to postpartum, fathers also told us that they were having worse quality sleep, that that they were more anxious, that they were more depressed, and that they had more overall mental health problems. So it appears that the very same changes that we’re linking up with father’s positive adaptation to parenthood were also putting men at some mental health risk and vulnerability when it came to sleep.
Phil Stieg
What about the hormone levels? Talk a little bit about what happens to the testosterone, how does that change?
Darby Saxbe
We know from research on both humans and animals that hormones change in males who become parents. So we’ve seen similar patterns in primates, and we also see those patterns in humans.
In men who become fathers, we tend to see decreases in testosterone levels, along with some rebound in the few years after parenthood. But those decreases seem to be adaptive in the sense that they’re linked with men’s tolerance of their infants and their patience for caregiving. So as men’s reproductive strategy is shifting away from maximizing opportunities for new mates and towards investing in the survival of their children, you see corresponding changes in their hormone levels.
And that’s something that we’ve seen in our data as well when we look at hormones like testosterone, oxytocin, and prolactin.
Phil Stieg
So men do see an increase in oxytocin, the kind of compassion hormone?
Darby Saxbe
Yeah, we found in our lab that when fathers were touching their infants more during a brief play interaction. Fathers who were more hands-on tended to have higher oxytocin during our lab visits. And what’s interesting is there’s a specific touch that we think of as characteristic of fathers. It’s called proprioceptive touch, which really means moving your baby around in space. So if you picture throwing your baby up in the air, juggling them, that was the touch that was linked with higher oxytocin levels in our dads. And that’s the touch that we associate as a father style of interacting with infants, whereas it’s been found in other research that more affectionate touch tends to track more with oxytocin levels in new moms.
Phil Stieg
Are there changes in the sleep hygiene? Like, is there less rem sleep, both equivalent in both men and women?
Darby Saxbe
Yeah. So we know that sleep gets really scrambled across the transition to parenthood and new parents. I mean, you don’t need a research study to tell you that. Anybody that’s brought home a baby knows that they don’t tend to sleep very well, and they wake up a lot during the night. One thing that’s interesting is there’s some evidence suggesting that men actually experience a greater sleep toll during infancy than women. And that’s because they often go back to work sooner. So they’re less likely to be able to take a long leave, and therefore they’re having to get up for the day earlier and to be able to function at work. Whereas if somebody gets maternity leave, they might be able to sleep a little bit during the day when the baby’s napping. So the extent to which men sleep is disrupted by a new baby really tracks with their participation in infant care, and particularly night time care. And what’s interesting is there’s a lot of variability across individual families. There’s also a lot of cultural variability.
It’s normative in the United States and in many Western industrialized countries that mom and dad sleep together in a bed and the baby’s in a separate crib, often in a separate room. But that’s certainly not a universal sleeping configuration. And globally, it’s actually more common to find mom and baby together in a bed and dad somewhere else. So the way that we organize our sleep lives is something that that affects father’s biological adaptation to parenthood. I think the name of the game here is that it’s really about context and about time and about how fathers are engaging.
Phil Stieg
I’m curious in listening to that about the cultural differences, say, between somebody lives in Africa, somebody lives in Russia, wherever. What are those differences in terms expectations of moms and dads? And then the corollary question is in first-generation whatever, first-generation Spaniard that comes to America and they’re married, are there differences?
Darby Saxbe
Yeah. I mean, there is a lot of culture that influences the way that we parent, not just in terms of mother versus father roles, but in general, just the way that we approach raising children. We see cultural differences in father’s adaptation and in father’s involvement as well. And that’s true, not just in industrialized societies, but really, if you look at more traditional, for example, hunter-gatherer societies.
In researching my book, I learned about a hunter-gatherer society called the Aka, which is in the Congo, where men are extremely hands-on with young infants and are within arm’s reach of a new baby about 50% of their waking hours. It’s very common for groups of men to sit in a circle all holding babies. At the same time, there are other traditional societies where there are prohibitions against fathers, even being in the same room as a new baby, and rules that men aren’t supposed to leave the house holding a baby for the first few years after birth. So there’s variability within those cultures. And of course, there’s also historical variability over time. Men’s role in fathering has really shifted just in the last 50 or 60 years to a place where we now expect new fathers to want to take time off, to be home, to be holding babies, to be changing diapers. And men of several generations ago didn’t necessarily have those same expectations.
Phil Stieg
Fathers that seem to be more invested have They get less sleep, higher anxiety, more depression, and psychological problems. So how do you put a positive spin on that or prepare them for it so they have a more positive experience?
Darby Saxbe
Yeah, an original subtitled that I considered for my book “was how fatherhood will make you sleepier, sadder, fatter, grumpier”, right? Because it is a mixed bag, and it’s a mixed bag for mothers, too. Parenthood comes with a lot of joy and excitement, but it also comes with isolation. It comes with repetitive caretaking of an infant who often can’t smile back at you. Who is not verbal and able to tell you, “Hey, thanks. I really appreciate the way you fed me just now”. So that’s a challenge for both men and women. And I think what we’re finding is that as men are getting more involved, they’re showing some of the same risks that we’ve long associated with new motherhood.
But I think there’s some good news if we take a larger view, which is that many parents and fathers, actually, even at greater numbers than mothers, say that parenthood is one of the most meaningful and satisfying activities that they ever participate in. Many fathers say that parenthood offers a source of richness and gives them a sense of purpose. And we’re living at a time when levels of isolation are high. Many more people are living alone than ever before. And young men, in particular, are falling away from sustaining institutions like marriage and education and family life. And so I think there is something really restorative about celebrating fatherhood as a way that men can connect to other people and to build a greater legacy.
And there’s also some good news from the perspective of the brain. So there have been There’s a number of studies that have come out recently looking at data from large data sets. One such data set is the UK Biobank. Analysis of those data sets find that when people have more children, their brains actually look younger in late life. So there does appear to be this neuroprotective aspect of parenthood. And what’s interesting is that it shows up in fathers as well as in mothers, which tells us that it’s not just the hormones of pregnancy that seem to be neuroprotective, but perhaps the experience of caregiving and the social integration that we can enjoy from being part of families.
Interstitial theme music
Narrator
Fatherhood can be a transformative experience—for humans and for other animals. But in some animal males, parenting doesn’t just change their brains and behavior. For those animal dads, even more extreme changes are to come.
whistling of a Darwin’s frog
That birdlike sound is the call of a Darwin’s frog, and the vocal sac in males serves a second purpose. After a female lays her eggs, her mate swallows the tadpoles, and broods them in his throat pouch. Once the tadpoles become tiny froglets, their father spits them out—in this case, having “a frog in your throat” isn’t a metaphor.
Seahorses are also caring fathers. They’re the only animal in which males become “pregnant.”
Male seahorses have special pouches in their bellies where females deposit eggs. Fertilization happens inside the pouch, which also provides the embryos with nutrients and oxygen.
A pregnant seahorse dad carries the growing babies and then goes into labor. He may pop out just a few babies …or a few thousand.
Fatherhood can trigger even more dramatic changes in male clownfish. You might know these orange-and-white striped fish from the animated movie Finding Nemo. All clownfish hatch with both male and female reproductive organs, and they develop first as males. They live in groups near coral reefs, and the biggest female is the dominant fish. If that female dies, the largest male in the group starts to change. Certain neurons linked to female reproduction increase, while neurons linked to male sex hormones, or androgens, decrease. A gene that converts androgens to estrogen becomes more active. The fish’s testes shrink, and its eggs prepare for fertilization. When the change is over, the once-male clownfish is now the group’s dominant female. If Nemo’s story had been scientifically accurate, after his mother’s death, his dad would have become his mom.
Theme music
And that’s not all: Nemo would likely have mated with this “second” mother—now the dominant female of their group. Though, having that plot twist in a kids’ movie would raise questions that many human parents might not be ready to answer.
Music out
Phil Stieg
So I think I resemble this remark that you made somewhere that I was reading where you said, Fathers are weird. What did you mean by that?
Darby Saxbe
That’s exactly right. Well, they’re weird in the sense that they’re rare across the animal kingdom. If only 5 to 10 % of mammals participate in care, that makes human And father’s one of that unusual 5 %. But I also think that fathers might be one secret to our success as a species. One thing that characterizes humans is how resilient and adaptable we are We can live in lots of different climates and lots of different conditions. And in part, that’s because we do have that alloparenting network of multiple caregivers that can support early life. And fathers can play a really key part of that network. When men choose to participate in care, we know that kids do better across the board. They have better educational outcomes, better employment outcomes, better financial stability, even better physical health. So fatherhood is an adaptation that I think comes in handy when we really want offspring to thrive.
Phil Stieg
What about being a father later in life? Is there an advantage or a disadvantage of that? Say you become a dad first time when you’re 40, 50, 60 years old.
Darby Saxbe
I think there are pros and cons. There’s not a lot of good research on that in particular. I I did have a chapter in my book about age because I thought it was really interesting that while women are relatively constrained in terms of their age range, at least if they want to become biological mothers, they have a window of maximum fertility. Men have the ability to become parents across a larger time span. So even in traditional hunter-gatherer societies, there are examples of men in their 70s and 80s becoming first-time fathers. And that comes with pros and cons, right?
When you become a father later in life, you might have more bandwidth to devote to your child. You might have a deeper sense of meaning. You might be able to feel like you’ve already conquered the workplace. So now you can settle down and be a more calm parent at home. But you also might feel a sense of loss that you might not be able to watch your child graduate from college or have kids of their own.
When I When I was reporting the book, I talked to a couple of dads who became fathers very young. I talked to a friend of mine who became a father at age 19, and I talked to another man who became a father in his 50s. And what was interesting is that both men told me that fatherhood had been wonderful for them and that they had done it at exactly the right time. So I think that tells us that there’s no right or wrong time to become a father. It’s about how you adjust to the role and how it fits into your life.
Phil Stieg
I was also interested in now where we have more same-sex parents. Physiologically, same differences? How does that play out?
Darby Saxbe
Yeah, we just have a handful of studies looking at the transition to parenthood in same-sex couples. So the research literature is really small in heterosexual couples. It’s even smaller in non-heterosexual couples. We do have a little bit of work from Ruth Feldman’s lab in Israel. She did a study of gay male fathers where one man was the primary and one was the secondary caregiver, and she compared them to heterosexual couples in which the woman was typically the primary and the husband was typically the secondary caregiver.
And she found that the gay men who had been designated within the couple as the primary caregiver showed more similar brain responses to the infant. Then they looked more like the moms in the heterosexual couples, whereas the secondary caregiver gay men looked a little bit more like the dads, which, again, I think, underscores this idea that men have very adaptive brains, and that it’s really about the parenting roles and the experience of parenting that shapes us more than it is about men can only do one sort of thing and women can only do one sort of thing.
Phil Stieg
Well, it seems to suggest that it’s not about the anatomy, it’s not about the physiology, but it’s about the socioeconomic environmental stressors that are placed on both moms and dads and the expectations for the role they should play.
Darby Saxbe
Exactly. It’s about our expectations. It’s about our cultural context. It’s about what works within individual families. And men can rise to the challenge, just as women can, to become great parents.
Phil Stieg
Give us some direction. What do people need to start thinking about being a better dad?
Darby Saxbe
That’s a great question. What is the secret to being a better dad? Well, we know that kids need consistency, they need stability, they need security. So the most important thing for young kids is an attachment relationship, which really just means not somebody who’s going to be ever present and never leave them with another caregiver, but really just somebody that they can return to, the concept of a stable base. I can wander off and discover the world, and there will be a stable base where I will always feel safe and secure. And that’s something that fathers can divide as well as mothers.
There’s also some evidence that fathers can be really valuable for young kids because they often have more willingness to test kids’ limits. Fathers are often the ones who are saying, You can climb another rung higher on the ladder of the playground slide. You can swing a little higher in the swing. So fathers encourage kids to take risks, be bold, be confident. And that’s something that in an era where people are bemoaning the helicopter parent and that we might be over-parenting our kids, parenting like a traditional dad might actually be the confidence booster that a lot of kids can benefit from.
Phil Stieg
What are your thoughts about the expression It’s quality, not quantity? Is that a reality in terms of being a good dad?
Darby Saxbe
Yeah, I think it’s both. I think it’s quantity and quality. I talked to a researcher who studies hunter-gatherers.
Phil Stieg
You want everything, don’t you?
Darby Saxbe
Yeah, I want it all. Well, kids want it all.
I talked to a researcher who studies hunter-gatherers, and I asked him, How has studying hunter-gatherer fatherers? Sorry, Let me say that again. I asked him, How has studying hunter-gatherer fathers influenced your own approach to parenting your kids? And he said, It’s actually just taught me that you have to just be around. You don’t have to be paying attention to kids every second of every day. You don’t have to be telling them what to do all the time. But you just want to be available in their space. They can model what you’re doing. They can observe what you’re doing.
So in hunter-gatherer societies, you have young kids are often following adults around and learning about adulthood from being able to observe elders. We don’t really have that kind of arrangement in contemporary societies because we have workplaces that are really divided from our homes. And so kids aren’t often invited to follow us around at the office and see what we’re doing. But I think that that ability to whenever possible just be present and be available is really helpful for kids. But it doesn’t mean that you have to be plugged into them at all times or, cruise directing every activity that they do.
And I think sometimes parents get caught up in the quality time idea and think They need to be totally laser-focused on their kids when they’re together, asking a zillion questions, giving them lots of instruction, when really kids want you to be a warm body sometimes. They want that stable base that they can come back to, but they don’t necessarily need you to be smothering them.
Phil Stieg
That’s right. I’m looking forward I’m good to it, I think. Policymakers for parenting, particularly for dads, what message you want to get out there?
Darby Saxbe
So I think because the transition to parenthood is so transformative, I think the single best policy is generous paid parental leave, maternity leave, paternity leave. I’m fond of the incentive and nudge programs that designate some leave specifically to dads because I think they do a lot to overcome cultural stigma and encourage men to participate more in parenting.
We also know those programs are good for mom’s mental health. When moms get more support, they’re less likely to get postpartum depression. So I think parental leave is my number one policy wish. But I also think we need to think about affordable child care. We need to think about high-quality schools. We need to think about high-quality after-school programs and summer camps. We need to think about how parents can afford college.
Those are things that in many countries are subsidized by governments. And so we do a lot of putting costs on individual parents, even though if you’re raising thriving, educated kids, you could argue that those benefits accrue to the whole society.
Phil Stieg
I think on a personal side, you talked about your father, who obviously transformed when he became a single parent for that every other week. Tell us a little bit about his emotional feelings about that.
Darby Saxbe
Yes. So my dad sent me a letter a few years ago in which he said, Those years after your mother left were really hard. I really struggled. But the saving grace was being able to take care of the three of you. That’s the thing that really sustained me. And I thought that was funny because we were really obnoxious kids. But he said, “It was a joy to get to know you”. And I really appreciated that. That, again, made me really appreciate how transformative fatherhood can be.
Phil Stieg
In reading through, how much it resonated for me in terms of my experiences of being a father — them not wanting me around, them not wanting to talk with me, feeling like I’m a total failure. But then I’ve done things in my life in terms of being successful. But by far and away, what your dad said, the greatest thing I’ve ever done in my life is being a dad.
Darby Saxbe
Well, I feel like my dad and you would have lots to talk about.
Phil Stieg
So take home message from you for our audience is what?
Darby Saxbe
Fatherhood is fascinating. It’s variable, it’s transformative, and there’s a lot to learn about it. So to find more, read my book. Yeah. Shameless promotion.
Phil Stieg
I think even if you do fatherhood a little bit wrong, it’s still the most rewarding thing that you can have in your life.
Darby Saxbe
Well, I think you said it perfectly.
Phil Stieg
Dr. Darby Saxbe, author of “Dad Brain; The New Science of Fatherhood: Why Great Fathers Are Made, Not Born” – Thank you so much for enlightening us, and it’s been a great pleasure being with you.
Darby Saxbe
Thank you so much. I really enjoyed our conversation.
