Video summary
The video explores the significant hormonal shifts that occur in men upon becoming fathers, specifically focusing on the drop in testosterone levels linked directly to active caregiving rather than just biological parenthood or gender alone. Drawing parallels from animal models like birds and primates, where high testosterone is adaptive for mating but decreases after reproduction begins to prioritize nurturing offspring survival, the discussion highlights a similar natural transition in human males. This hormonal adjustment serves an evolutionary purpose by shifting male behavior away from aggression and risk-taking toward stability and investment in the partner relationship, ensuring that fathers are less likely to engage in dangerous activities like reckless driving or fighting while protecting their children.
As testosterone levels decline due to increased involvement with infants, men typically exhibit behavioral changes such as reduced territorial aggression and a heightened motivation to maintain stable pair bonds. The transcript illustrates how this biological shift correlates with improved health outcomes, including lower substance use and greater conscientiousness regarding medical checkups. However, the video also notes that external factors can temporarily spike testosterone; for instance, being around women or handling weapons can trigger risk-taking behaviors driven by a desire to display masculinity. This creates an interesting interplay between bottom-up biological responses and top-down social expectations where men must consciously override these impulses to prioritize their family's safety over proving themselves in competitive scenarios.
The conversation critically examines the societal misconception that low testosterone equates to lost masculinity, arguing instead that true manliness lies in adaptability and fulfilling one's role as a protector and guide for the next generation. The speaker warns against using testosterone supplementation during fatherhood, citing anecdotal evidence of men lacking patience with their babies when artificially maintaining high hormone levels, which could undermine the very nurturing environment required for child-rearing. Ultimately, the video concludes that positive masculinity is defined by flexibility in response to context—being able to lower aggression and risk-taking when necessary for parenting rather than perpetually striving for elevated hormones at all costs—and suggests that being a good father may be one of the most inherently masculine acts possible.
Read the full video transcript
What about impacts on hormones in men?
>> Yeah, so we see changes in testosterone
around the birth of a new baby. We don't
know as much about how hormones change
in adaptive or step parents because
there just isn't a lot of research about
this. Most of the work is on early
parenthood and it most of it is focusing
on biological parents.
>> Mhm.
So testosterone gets tuned down?
>> Mhm.
>> Does that increase with caregiving?
>> Yes.
>> In fact, does that happen without
caregiving?
>> No.
>> Right.
>> So it's linked as are the brain changes
to dad's participation in care.
>> Okay.
>> So we see this not just in humans, we
see this in animal models as well.
You are probably familiar with the
challenge hypothesis, the idea that we
want high levels of testosterone under
certain circumstances. It's adaptive for
testosterone to drop in other
circumstances. So
>> birds are the classic example.
Testosterone levels rise at the start of
breeding season when birds are competing
for mates, they're looking to spread
their seed, they want as many
opportunities as possible so they need
status to try to find a partner. And
then after mating has been accomplished,
it's immunologically costly to maintain
perpetually high levels of T,
testosterone naturally decreases and the
reproductive strategy is shifting
towards more nurturing. So instead of
maximizing our numbers of babies that we
can produce, we want to maximize the
odds that any given baby is going to
survive. And our hormones kind of follow
suit.
>> Mhm.
>> And you see it in primates, you see it
in rodents as well as in humans. You see
these natural shifts.
>> What
What are the behavior changes that
happen in men
based on their hormones?
>> So typically when testosterone
decreases, it's serving a function
whereby dads are getting
more invested in the partner
relationship. They are more interested,
more motivated to maintain a stable pair
bond, and they're less aggressive. So, a
lot of the work in in rodents has looked
at sort of territorial aggression, and
you know, when you see a new pup in the
nest, do you want to kill them or do you
want to care for them? And testosterone
levels can sort of modulate where you
end up.
>> Mhm.
>> along that continua.
So, we want, in general, if anyone is
spending a lot of time with infants to
be less motivated to kill and more
motivated to care.
>> [snorts]
>> Risk-taking behavior as well.
>> goes down. And you see that, you you
know, you you see actually in some ways
health improvements. We we can talk
about dad bod at some point, I'm sure,
but uh you see some health improvements
in terms of less risky driving, less
likely to get into fights, lower levels
of substance use,
being more conscientious about doctor
checkups. So, all of those behaviors
that keep us alive and ready to provide
for our offspring
>> Blame it on the testosterone.
>> shift, sure.
>> Blame it on the testosterone. Yeah. You
know, one one of my favorite studies
around um risk-taking behavior and uh
male and female relationships,
looking at studies of men crossing the
road and the distance from them to the
nearest car in the presence of women or
without the presence of women.
>> Yeah.
>> And they If there's a woman there, it's
at three times closer. Like, dude, look
at how hard I am, harder than this car.
>> But
>> Yeah, that doesn't end well either way.
>> Typically, you know, a fight between you
and a car, you usually lose.
>> Yeah.
>> However,
the thing that's interesting that like
we know that testosterone can change. If
we had um a ton of weapons on this
table, like axes and and spears and and
guns and stuff, and me and the guys
walked around and like picked them up
and played with them, our testosterone
go up.
>> Yeah, and I would be terrified.
>> It's very
you would That that happens after.
That's what The way that we close the
show out is by wielding weapons inside
of this one.
>> Okay, yeah, remind me to get out of here
first.
>> second. Now, we're live action
role-playing in the Middle Ages. Um so,
that's
sense the fact that we can be so
reactive as men. We talk about how
hormonal women are. And yes, but
reliably, men much more unreliable.
Similarly,
>> Yes.
>> a lot of hormonal changes, but they
don't happen on the same sort of lunar
schedule. Um but, what that must mean
I don't know whether this will be the
primary driver because a lot of it's
like there's a girl there and I'm just
going to show how how hard I am and how
how masculine and the risk-taking.
>> Yeah.
>> [snorts]
>> But, also there'll probably be a bit of
an increase in testosterone and that
might push it a little bit more.
>> Yeah.
>> And the same thing will be presumably
happening here as well that there's a
relational component, there's the sort
of top-down baby must be here for baby,
must not drive recklessly or text while
I drive, etc. But, also there is this
sort of bottom-up environment that's
being created which encourages us to
behave in that way, too.
>> Exactly. Biology and culture work
together as they do in so many
ways in parenthood.
And and yeah, I think it's really
interesting the extent to which our
culture is kind of in flux between
different models of fatherhood.
And so, you know, are are we low T dads
or high T dads? But, there's plenty of
work suggesting that, you know, in
athletic competition,
in other opportunities for men to raise
their status, you see changes in
testosterone. So, testosterone, you
know, I think we can talk about
testosterone supplementation and what
that means for men who want to be dads.
I think to me what is adaptive about
testosterone as with any other hormone
is that it's responsive to context. And
we want to be flexible because we want
to have a biology that sets us up to
achieve our goals.
>> You're saying that if you were to be
taking testosterone enhancement whilst
becoming a father, you think that you're
able to outwit biology's
uh
um uh uh
well-proven environment that it's trying
to create inside of you, and you're just
plowing through it by injecting yourself
with T.
>> I think that's the fear. That's the
risk. And and anecdotally, I hear from
moms who say, "Yeah, my husband's been
taking T, and he's has no patience with
the baby." Who knows? We need better,
more rigorous studies to see if that's
actually true.
>> Yeah, but he's jacked.
>> But exactly. [laughter] So, there's a
trade-off.
>> growing up with a jacked dad. Come on.
>> in some contexts, that could be really
good. Like if you have to fight your way
out of a cage to get a leg of lamb for
your kid, then you probably want high
testosterone in early parenthood. But
that might not serve the style of
fatherhood that is more desired.
>> Presumably as well, if that environment
was the one that you were in, your body
would detect it and go, "Hey, that's
some more testosterone for you." As
opposed to you going, "No, shut up.
1,000 ng/dL is absolutely fine." Like
Like
>> Yeah, well, in riskier environments
>> you know better than your body does.
>> Yeah, when you're in a riskier,
competitive environment, men want higher
testosterone. That's going to serve
their goals. It's not always going to
serve their goals when they're in a
parenting environment. And so, you know,
I think the thing about supplementation
is we sort of have this idea that
manliness is about maintaining
perpetually high T.
>> Yep.
>> I think actually positive masculinity is
more about adaptability, being flexible,
and showing up in the way that you need
to for changing situations.
>> Well, what a
horrendous own goal it would be
if you decided to keep your testosterone
high in an attempt to show your
masculinity and in the process ended
your lineage.
>> Yeah.
>> Like well done, dude. Like you blew
through all of the warning signs that
you should have been tuned down from.
>> Yeah.
>> So yeah, I guess testosterone drops when
men become engaged fathers, right? So
it's some men will hear that and think,
"Okay, so fatherhood makes you less of a
man."
>> Right.
>> Do you think that the fear of losing
masculinity by caregiving is actually
driving avoidant fatherhood? In some
ways, maybe.
>> This was something I worried about when
writing this book and trying to
summarize the science around fatherhood
is that the subtitle I joked for a while
would be "Fatherhood gives you a smaller
brain, makes you sleepier, sadder,
fatter, and have lower testosterone, but
it's really good."
>> Jared.
>> It'll give you
So that I don't think that would That
wouldn't sell very many books.
>> Yeah.
>> And we've talked about some of the
benefits of fatherhood, like an
increased sense of meaning and purpose
and neuroprotection in late life. I
would argue that being a good dad is one
of the most manly things you can do.
You're literally rearing the next
generation. You're guiding them, you're
protecting them, you're inspiring them,
you're teaching them. So when you think
about what is masculinity for,
I would argue that in some ways it's for
your ability to be a good dad. So I
think we confuse like just having a
certain hormone level equals
masculinity.
And I would counter argue it's more
about what is your social role and how
are you showing up to do the things that
are needed of you.
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