The Painful Psychological Cost Of Becoming A Dad - Darby Saxbe - #1129

**Chris Williamson** (0:00)
I'm sorry it's taken so long, but merch is nearly here this Friday, the 31st of July at 12 midday Central time or 6pm UK time.
The brand new Modern Wisdom merch goes live. Head to mwmerch.com now to sign up. You'll get first access, and once this is sold out, it's gone. Never to be printed again. You've only got six days to be able to buy. So head to mwmerch.com now. Most people are familiar with mum brain, but you found that dad's brains go through a bunch of changes too.

**Darby Saxbe** (0:25)
Exactly. Yeah, so I've been looking at new fathers in my lab over the last decade plus. We've scanned men when they're midway through their partner's pregnancy, and then again, after they have their first child, and we find that the brain, and I should caveat, this is not a bad thing, loses gray matter volume across that transition to fatherhood.
So the patterns look similar to those that have been observed in moms, and they seem to be of smaller magnitude. They're more variable, and they're more tied to dad's parenting experience.

**Chris Williamson** (0:59)
How does it differ from mum brain? What are the biggest differences?

**Darby Saxbe** (1:03)
So new moms lose about 2.5 percent of their gray matter volume across the transition into first-time motherhood, and they lose volume in parts of the brain that are really linked to hormones. So that includes not just the cortex, which if you think about the outer layer of brain tissue, that does a lot of our higher order thinking and reasoning. It also includes what's called the sub-cortex, which contains our amygdala, our ventral striatum, which processes reward, and number of other structures that are linked with drive and gut feelings.
Dads change mostly just in the cortex, which is that sort of executive functioning, thinking and reasoning part of the brain.
Moms show profound changes across the whole brain, and dad's changes are, like I said, smaller in magnitude. So dad's is about 1% of their gray matter volume. And my lab found that this was totally tied to dad's parenting time and investment. So dads who felt more bonded with their babies before birth, they were more motivated to take time off after birth, they spent more day-to-day time with kids in the first few months, and they reported feeling more bonded and having more pleasure in interacting with their kids, those dads showed the biggest brain change.

**Chris Williamson** (2:19)
How would you categorize the change in fatherhood over the last few generations?

**Darby Saxbe** (2:23)
There's been a dramatic change. So by some estimates, dad's daily time in parenting has tripled or even quadrupled compared to the father knows best dads of the 50s and 60s. So there's been a huge uptick. And what's interesting is that there was an inflection point around the pandemic, where men who might have been commuting to an office and maybe missing a lot of the day-to-day stuff with their kids suddenly had the experience of being hands-on parents in a different way.
And a lot of people wondered whether that uptick would persist. And it has. So millennial dads are spending more time with kids than any other generation of US dads. And there's evidence that Gen Z dads are spending even more time than millennial dads. So there's been a pretty dramatic shift.

**Chris Williamson** (3:15)
How does modern fathering differ from hunter-gatherer societies?

**Darby Saxbe** (3:19)
So it's interesting. So in my book, I talk about the model of hunter-gatherer fatherhood, the ACA, which is a society in the Congo where men spend a lot of time within hands' reach of infants. And they're very involved in infant care. And what's unique about the ACA, and this quality is shared by a number of other hunter-gatherer societies, is that they have a very egalitarian, flat social structure. And there's a lot of cooperative resource gathering. So we know hunter-gatherer societies are the context in which we spent 95% of our human history. So they tell us something about the environments within which we adopted, within which we evolved. And we know that women contributed a ton of calories. So when people say it's unnatural for women to work, in fact, women have been economically productive for most of our human history. But in the Aka, the main form of resource gathering is joint cooperative net hunting. So couples work together to gain resources for the society.
And as a result, really differentiated specialized parenting roles don't make very much sense, right? They would not be economically adaptive. But you see other models, even within Africa, we talk about another society, the Kipziges, which is a day's drive away, where there are strict prohibitions against men picking babies up in the first year after birth. No way. So you'd never see a man carrying a baby outside his own home. They're not supposed to share a sleeping surface with babies, because it's considered that the manliness of the father will disrupt the infant's rearing and that the infant will compromise the father's masculinity.