The Art of Manliness - #410： The Male Brain

00:00:00.000 brett mckay here and welcome to another edition of the art of manliness podcast there's an argument

00:00:19.640 out there that gender differences are just the product of socialization implicitly and explicitly

00:00:24.520 the argument goes culture tells men and women how men and women should behave my guest today

00:00:28.700 argues that drivers of male and female behavior are a little more complex than that in fact about

00:00:33.020 50 of the differences between men and women are rooted in our biology beginning with how our

00:00:37.240 respective brains form in utero her name is louanne brisendine she's a neuropsychiatrist professor at

00:00:41.900 the university of california san francisco and the author of two books the female brain and the male

00:00:45.880 brain today we discuss the latter work and the trajectory of the male brain takes from prenatal

00:00:50.420 life all the way through old age we begin our conversation discussing how a mega dose of

00:00:54.320 testosterone in the womb wires a male brain differently from the female brain and how that 1.00

00:00:57.980 influences how boys socialize and learn during childhood louanne then discusses how the male

00:01:02.220 brain is restructured again with another mega dose of testosterone during puberty and the impact that

00:01:06.460 has on a teen's behavior she then walks through what happens to the male brain when a male falls in love 1.00

00:01:10.940 has kids and enters mature adulthood consider this podcast an intro guide to how your brain works

00:01:16.140 assuming you're a dude listening to this though female listeners will also get insights on why the 1.00

00:01:20.900 males in their lives act the way they do after the show's over check out the show notes at

00:01:24.280 aom.is male brain luann brisendine welcome to the show thanks for having me bro so you published a

00:01:41.660 book a few years back called the male brain which is this fun narrative scientific narrative of what

00:01:48.060 happens to a male brain from fetus all the way to elderhood so there's a lot of you know discussion

00:01:55.600 out there about the basis of gender and sex right is it biological is it cultural so what's your take

00:02:02.940 is it all biological or does culture play a role in how men and women behave and think well you know

00:02:08.120 there's been a big discussion for many years between psychologists and biologists and the psychologists

00:02:17.120 look at culture and upbringing and the biologists tend to look at the biology the hormones the genetics

00:02:24.780 of of everything that they look at but including gender and um if you ask a biologist what part is

00:02:32.500 biology and what part is culture and upbringing biologists will tell you it's about 50 50 from their point

00:02:40.100 of view and if you ask psychologists how they look at it which is culture and which is biology they will

00:02:46.480 say you know it's about 50 50 so really there is no disagreement there may be disagreement in the

00:02:53.820 details but but in the broad sense there's no disagreement that culture has a huge part if not

00:02:59.340 50 to play in how our behavior is shaped by our culture how our behavior is shaped by our family of upbringing

00:03:08.120 and our schooling etc etc because things that boys are quote-unquote encouraged and allowed to do

00:03:16.220 uh versus things that girls are encouraged and allowed to do are somewhat different and girls and boys tend to

00:03:23.780 um if you left to their own druthers they will actually sex segregate during grade school years um and enjoy

00:03:32.440 playing with same sex more than they do playing with opposite sex and that seems to have something 0.69

00:03:38.280 to do with just the actual interests that boys have in in things that make a lot of noise and explosions

00:03:45.160 and um kind of the come on guys let's go get them kind of the team effort and fighting off the enemy

00:03:51.580 girls will do that for a while with the boys but then they get kind of bored with that and they will 0.98

00:03:56.660 they want to they will like to do more of the category of play called um role play um they like

00:04:04.840 to play like you be the doctor i'll be the patient or you be the mommy i'll be the daddy and then um

00:04:10.260 role play these uh roles that also are in relationship to the other more than kind of come on guys let's go

00:04:17.340 get them so there's a it's a big difference um and that's just kind of a brief summary of a type of thing

00:04:23.000 that boys will do that with girls maybe for you know one one play of you know 15 minutes and then

00:04:30.000 they want to go off running with the boys come on guys let's go get them or what whatever they're

00:04:34.120 doing that's more active so that is a stereotype but actually in um all of eleanor mackabee's studies

00:04:41.800 um from kids ages about five to age nine ten eleven twelve they really prefer to play the games that

00:04:52.840 the their same sex peers want to play so that's something that's noticed of course then things

00:04:58.380 start to shift when the hormones of puberty start to blast in right well let's talk about the hormones

00:05:04.940 like i like at the beginning of the book you talk about you kind of list this cast of characters

00:05:08.600 so what are the hormones that influence both male and female brains so if we start from the very

00:05:14.860 beginning brett on terms of like at the moment that the sperm meets the egg that sperm is carrying an

00:05:20.660 x chromosome the baby will be girl caries of y will be boys alike right at that moment our our gender is

00:05:28.040 set uh genetically and at about eight to ten weeks of fetal life the tiny testicles in the male fetus

00:05:36.060 start to pump out huge amounts of testosterone already and they marinate the body and brain and change it

00:05:41.960 into male in the girl there is no testosterone and so her system develops without testosterone and 0.94

00:05:50.680 ends up being female at birth so by the time we're born our our um if everything goes according to plan

00:05:58.420 we're either male or female and at birth um after from about one month to 12 months in a boy his testicles

00:06:07.600 continue to pump out almost adult male levels of testosterone during that first year of life

00:06:14.400 um and girls it's about from age one month to 22 months so her body start her ovaries are pumping out 1.00

00:06:22.040 estrogen for those first two years of life and we call that phase of hormonal development infantile

00:06:29.340 puberty because of these huge levels of their um sex determined hormones we don't really know much

00:06:38.160 about infantile puberty in terms of what it's doing and how it's really developing uh brain and body

00:06:43.980 circuitry but biologists continue to think that it's most likely to do with it's priming the whole

00:06:50.100 fertility system in humans um and um other other animals do not have infantile puberty so that's

00:06:58.300 something particular to us humans uh then of course we have that pause called the juvenile pause or

00:07:07.020 in the vernacular it's called childhood childhood is a time when female hormones and male hormones from 0.92

00:07:14.560 the ovaries or testicles are very very low level and basically females and males during childhood have

00:07:20.800 about the same amount of estrogen testosterone as the opposite sex so that's a time of quiet hormones 0.99

00:07:28.160 with very very low levels um until the ramping up of puberty and males at about nine years old

00:07:38.620 nine to eleven years old their testicles start to respond to signals from the pituitary and brain that tell

00:07:45.280 um the testosterone making cells to turn on and between ages of nine and fifteen males go from a very low

00:07:53.660 level of testosterone up to a very up to um you know 200 times as much so you're up at the two three

00:08:02.640 400 level by the time you're 13 or 14 at the time when the first wet dream happens and that basically is

00:08:09.600 an indication that the system the male reproductive system is primed and ready to go okay let's talk

00:08:16.660 about so you're born you go through this infantile puberty we're not exactly sure why or what's going

00:08:22.580 on but there's an indication that there's some sort of structural reorganization going on the brain and

00:08:27.360 the body priming it for that fertility period later on so let's talk about some of the differences that

00:08:33.500 we see between boys and girls during childhood they have the same amount of hormones with testosterone

00:08:38.940 estrogen but as you said there are differences you mentioned sort of the different ways that boys and

00:08:43.460 girls socialize and play um what are some other differences like how between boys and girls

00:08:49.820 during childhood well one of the things that researchers have found is that um they've had

00:08:56.200 several studies where they'll take boys at age six seven they'll let them play together for 30 or 40

00:09:00.680 minutes and then the observers kind of uh rank them according according to like who ended up being the

00:09:07.140 alpha boy and all the way down um to the bottom of the group and that's kind of called establishing

00:09:14.220 hierarchy and girls don't tend to do that and they have uh other types of of play and kind of um 1.00

00:09:21.260 different types of aggression than boys do but it's a little bit harder to establish a real hierarchy like

00:09:27.160 boys do very quickly if you bring those boys back together at about age 11 or 12 they haven't seen each

00:09:32.720 other in years and years so they have a couple of studies where the boys basically re-establish the

00:09:37.080 same hierarchy as they had at that younger age at six or seven which is kind of remarkable if you

00:09:42.300 think about it the um so there's this hierarchical play that's different different in boys and girls

00:09:49.040 um and they just they basically there is it's not clear whether that those boys just have more um

00:09:58.840 more hormones more aggressivity more charisma or all of the above that end up being the leaders of

00:10:06.000 the pack but there is a very kind of clear leadership hierarchy established in boys pretty quickly that's

00:10:13.700 not the same in girls and how do boys say learn right different how do how do they interact with

00:10:20.800 learning or paying attention that's different from girls i think that's a fast the learning difference

00:10:25.840 between boys and girls is one that's of course had a lot of airplay and a lot of schools that are

00:10:30.620 trying to address this because um an example is is math and they were basically the study looking and

00:10:38.280 trying to have how to get girls to learn math more easily or more quickly or learn math more like boys 0.69

00:10:44.180 learn math and in in the in the studies that were looking at that they basically discovered that the

00:10:49.020 way the boys learn boys fidget and wiggle and and and when they're learning math they kind of they

00:10:55.240 they they they wiggle and kind of actually embody if you will they embody uh the equations or they

00:11:01.520 embody the concepts in some way um so if you can't they stopped asking the girls to sit still and have the

00:11:09.400 girls start you know wiggling around and doing some of the same kind of embodiment movements that the 1.00

00:11:15.340 boys were doing and show that actually the girls learned uh learned math much more quickly so that's

00:11:21.020 that's an interesting study that a lot of people have made a lot of it we don't really we really

00:11:25.440 still do not understand very well um i think that um the idea that you want to have um boys sitting

00:11:34.140 still all the time in a classroom and you remember that one of the things is is that most teachers of

00:11:39.620 elementary school age age kids are female by and large and so there's been a big emphasis on like

00:11:47.060 you know the girls who can sit still and draw and write and be and be um not jumping up and out of

00:11:53.720 their chairs all the time are are the students who get praised by the teachers the most and it's usually

00:12:00.060 the boys who are being considered being disruptive etc so they're getting a lot of sort of negative

00:12:05.820 feedback in the classroom about their lack of ability to sit still so people have started

00:12:12.200 thinking well maybe this isn't such a great idea to have everybody sitting so still you need to let

00:12:17.120 each kid but in particular boys need to be able to move around uh to learn better one of the

00:12:23.460 interesting insights i got from your book was sort of the mood and emotions of boys and girls so

00:12:28.560 traditionally males in most cultures are expected to be stoic females are allowed to be emotional but you

00:12:34.760 highlight there's research that suggests that infant boys um even young you know young boys they tend to

00:12:41.520 be more emotionally i don't know what's the word sensitive than girls like they they get upset more 0.85

00:12:47.900 easily and take a little longer to calm or soothe yes so the the uh an interesting thing is it's a

00:12:54.420 little bit of a reverse you know in adulthood but in the child in in little boys basically uh get their

00:13:01.020 nervous system more jangled and are more and are more sensitive to many things than little girls 0.96

00:13:06.560 and it takes them a little bit longer to calm down and to soothe them lots of moms you know certainly 0.62

00:13:11.560 notice this and they just behave accordingly in terms of the soothing soothing of of little boys but

00:13:17.080 it's interesting that their systems are wired to be um more reactive and more sensitive in in childhood

00:13:23.940 in little kids than maybe we're talking about like under age five or six and i guess they learned how

00:13:30.740 to that's where we kind of see the interplay of culture and biology the the culture expects them

00:13:35.080 to be stoic so they learn how to tamp that down well you know the i think that the biggest the

00:13:39.620 was the most well-known adage is boys don't cry or you know you know suck it up don't you know

00:13:45.480 suck it up let's let's stop the crying there's no use in crying like act like a man right i mean

00:13:50.400 especially and the fathers the fathers tend to be that the fathers tend to be the ones who carry

00:13:56.540 that culture to the boys mothers won't mothers don't say that kind of thing to their boys if 1.00

00:14:01.940 they don't say like you know stop that crying why don't you man up you know stop making it stop

00:14:06.980 making like a baby i mean mothers don't tend to say that it's usually fathers who enforce that mandate

00:14:13.600 upon their sons because you know they don't it it upsets the fathers to see that maybe their sons

00:14:20.860 will be shunned because they're quote-unquote a cry baby and it makes the father feel look bad

00:14:27.120 so you mentioned boys tend to socialize in teams they establish hierarchies they're interested in math

00:14:33.680 they sort of embody that through you know physically sort of becoming the equation physically um what are

00:14:39.780 some other differences i think you highlight that boys tend to be interested in things or objects and

00:14:44.260 girls people so i think this the the idea that boys are interested in in things and especially in

00:14:50.300 toys that move um even little they've done some studies in young primates then the males little

00:14:56.660 male primates prefer uh toys that actually have wheels and move and um little girls will play out 0.99

00:15:03.480 they're not they're not so particular as little boys are about things that move and things that are

00:15:08.460 uh that are active so that the toy choice the toy choice in in boys and girls you know you might

00:15:15.340 have one out of ten boys preferring more girls things and one out of ten girls preferring more

00:15:21.040 boy toys so there's that it's important to realize that the male and female brain are more alike than 0.99

00:15:25.540 different we are the same species after all so um there and there's huge amounts of overlap so we're

00:15:31.560 just we're talking about some things that are quite quite quite amount of stereotype here right okay so we

00:15:37.980 we've we've gone through childhood hormones are about the same between boys and girls but despite

00:15:42.140 that similarity there are some differences that show up and i'm guessing i mean i know you said like

00:15:47.440 they don't know why the differences they they it could be the the surge of testosterone that you

00:15:52.440 received in the fetus and when you're an infant might play a role so somehow that you know remember

00:15:58.620 from like eight weeks of gestation the testicles are working overtime to make testosterone so

00:16:03.800 testosterone is a really is the really important sculptor the sculptor of manliness of manhood of

00:16:11.520 of the male brain circuits of the male body you know testosterone kills off any of the female parts of the 0.99

00:16:18.720 organs you know because we have we have both organs where we all have both both organs in us at some

00:16:24.660 point and then testosterone kills off all of the uh the female organs like the tissue that would become 1.00

00:16:29.860 a uterus or vagina that is killed off by testosterone and the male organs are stimulated so there's 0.86

00:16:35.980 testosterone is quite a um uh a biological sculptor if you will of of the male model okay so it goes

00:16:45.160 through that sculpting process uh in in utero shortly after birth but then there's another reconstruction

00:16:51.660 that happens at puberty that we all know about um so we all know the the secondary i guess is that

00:16:57.620 where the secondary sexual like what is that called yeah the secondary like the deeper voice hair you

00:17:04.840 know mustache and beard and general hair all that stuff all the stuff that you start feeling awkward

00:17:10.900 about right around 12 or 13 kids are embarrassed about yes yes i know we had we used to have a

00:17:16.200 grandson and he would actually for a while he was he would talk to us on skype about various things

00:17:21.220 as he was going into puberty he used to count the number of pubic hairs and report back to us about how

00:17:26.380 many and then it was very noticeable though when he was counting at about 25 he stopped we didn't hear

00:17:33.160 from him anymore on that count so it was yeah it was all it was all lots of fun and exciting the

00:17:38.220 beginning and then all of a sudden it's like uh don't think this is too cool not cool anymore okay

00:17:42.840 well let's talk about what happens in the brain because that's what the focus of your book is so what

00:17:45.880 is going on in this sort of this reconstruction of the brain during the male brain during puberty

00:17:50.600 so basically you can just imagine it's a tsunami of testosterone just starts to hit the male brain

00:17:56.400 and it hits those areas that have been primed in his brain to do what's the the most important thing

00:18:04.080 from a genetic perspective for a male to do is to go sow his seed right you um that's the idea is to get 0.73

00:18:12.180 your get your dna into the next generation which requires seeking out fertile females and inseminating 1.00

00:18:20.020 them so that that is kind of like the basic mission of the male and um it's it's important to realize

00:18:27.800 that because that's just how a lot of the wiring that's all turned on during puberty which can be

00:18:32.900 quite confusing to boys um i'm sure most guys i talked to remember this vividly and all of a sudden

00:18:40.640 every pair of breasts that walk down the street and you know every every kind of uh uh buttocks or 1.00

00:18:47.780 sexual innuendo is it's all all of a sudden just kind of blares out at you and um there's this

00:18:56.060 i can remember i can remember my son when he at that age that he was he would i was interviewing i

00:19:02.380 said like i'm writing part of this book and he was about 13 i said what what do guys your age say about

00:19:07.360 you know when girls come to school in very skimpy clothes in the spring and summer and he says well 0.94

00:19:12.340 mom pretty soon you just you feel like you can't take your eyes off them but and at first you feel

00:19:17.120 like a perv and then you realize that all the other guys are thinking the same thing so so i think that

00:19:23.020 boys go through this period where they're really doing what their biology tells them to biology and

00:19:28.600 hormones tells them to do and yet they have a lot of of of awkward feelings about what that means

00:19:34.500 about who they are but that's just you know a part of the unfolding of this process in early

00:19:40.280 adolescence so besides the amplification of you know sex and what other behaviors does testosterone

00:19:47.380 start to encourage or promote in boys so i think another fascinating area that um i think we don't

00:19:55.520 know enough about yet that's very interesting is that the male facial features and the male looking at

00:20:03.040 other faces um the testing of looking at faces and then while you're in a brain scanner if males start

00:20:11.360 to look at faces that are happy they you know they'll report that they're happy but if then they start to

00:20:17.500 report faces even that are what are called neutral faces and they they report them in adolescent boys they

00:20:23.720 report them to be angry faces and of course a really angry face that reports angry but all of a sudden

00:20:29.420 even neutral faces are starting to look a little angry to them so you know you as an adult you will

00:20:37.740 say well they're kind of misreading that a little bit and the misreading of that is is because something

00:20:43.860 is happening in their brain to be looking at other faces to see them as being a bit angry um that may be

00:20:50.660 something to do with self-preservation that you know that's probably old old wiring in the male brain

00:20:58.100 from you know the our most successful great great great great grandfathers you know were the ones who

00:21:03.720 survived and the ones who didn't get killed off by somebody else and were able to you know procreate

00:21:10.540 and have us be their offspring so it's really important to to know what ancestors the way they

00:21:17.120 survived and what characteristics in the male brain allowed them to survive so we mentioned boys even as

00:21:24.000 children uh are very hierarchical i imagine this only gets amplified during puberty yes it continues to

00:21:32.080 play out um and i think that because boys different boys you know some boys reach their full height not

00:21:38.080 until they're in their early 20s on the other end of the spectrum and some boys reach their full height

00:21:43.740 at 13 or 14 and so um something about the rapidity of their growth and their muscles their height um

00:21:51.160 certainly allows certain boys to be much more um uh to maybe change their place a little bit in the

00:21:59.040 hierarchy but um the testosterone is making them much more uh noticing any microaggressions microaggressions

00:22:06.860 from others um and i remember when my son first started driving you know 16 17 microaggressions from

00:22:13.320 other drivers that i didn't even notice you know when i was in i had to be you know his uh co-pilot there

00:22:20.440 for a while microaggressions from other drivers drove him crazy at that stage so but those kinds

00:22:26.640 of things play out in the classroom they play out on the you know on the playground that play out in

00:22:31.100 in their lives so that's that's part of the sort of uh hierarchical and just how boys start noticing

00:22:37.680 uh and maybe what we call hyper-cathecting or hyper-noticing um and being vigilant about negativity or

00:22:47.920 maybe angry intense of other people right so here's an interesting question that i was thinking

00:22:53.380 about so you have all this testosterone coursing through boys at puberty um which testosterone is

00:22:58.680 supposed to you know make you more ambitious have more drive take more risk yet you know high schools

00:23:05.620 across the country teachers reporting at this period of time boys become very disengaged from school

00:23:11.840 so what's going on there why is it that you know they have this this this milieu of hormones that's

00:23:16.700 you know driving them to be the best so they can uh you know pass on their seeds sow their oats as you

00:23:21.980 said but like they're disengaged from things like school or other aspects of life we know we don't

00:23:27.360 entirely understand what that's about but that we what we do know so i'll tell you we know what's going

00:23:32.400 on in the brain at that time that the brain is having a huge like the second what's called the second

00:23:39.260 brain largest brain development in the human uh growth pattern is in teenage years and what's

00:23:47.140 happening is if branches on a tree are just sprouting all through the brain i mean there's so many more

00:23:52.700 connections than you'll eventually need so there's all this brain growth that's going on like mad

00:23:58.720 probably related to growth hormone and a lot of other types of growth like so not only is the body

00:24:04.420 growing that the brain is actually growing and it's overgrowing and um one of the one of the things

00:24:10.940 that happens that a lot of uh schools are trying to address right now is that the sleep the wake cycle

00:24:16.520 changes hugely the the going to sleep doesn't happen until later in the evening you know you don't get

00:24:22.840 sleeping want to go to sleep till midnight maybe and then really you need more sleep at age 14 than you

00:24:28.580 did at 10 you know most teenagers really need about between 10 and 12 hours sleep a night

00:24:34.780 because of all this growth and brain growth that's going on and growth hormone is secreted at night

00:24:40.900 time so you know it's a really important time for that so boys may be sitting in classrooms actually

00:24:47.120 their brain is still asleep it hasn't woken up yet it probably won't wake up till four o'clock in the

00:24:51.460 afternoon or something you know it's very there's a there's a there's what's happening in the brain under the

00:24:56.460 hood if you look under the hood the apathy and just not being able to focus and pay attention and

00:25:01.880 actually it's that thing is shifted whole a whole hour later in boys than in girls so girls go to 1.00

00:25:09.140 sleep earlier and they can wake up earlier boys go to sleep later and that will reset itself to be

00:25:14.140 matched between males and females at about age 30. Interesting and I was what if my what I understand

00:25:19.960 about testosterone is that it also promotes dopamine production which is sort of the you know makes you

00:25:25.440 want to do things and I guess if you have too much dopamine like you need more dopamine to like get

00:25:30.300 motivated it's like boys might actually be bored right they need a lot of stimulation to get to get

00:25:35.380 excited about something and I think that's one of the compelling parts of video games you know the the

00:25:40.140 video games that are the singer shooter shooter games where you're basically just all you have to be

00:25:44.780 all alert all the time in every moment to see who's coming from which side and you know that and I think

00:25:51.640 that that's an example of things that really get boys attention gets their brains attention and

00:25:56.360 honestly the stuff that's going on in the classroom cannot hold a candle to that it's so slow it's just

00:26:02.460 so boring it's just like it's not getting their attention so you're right it's that they're it's not

00:26:08.500 that they have attention deficit disorders it's that they're not interested in paying attention to how

00:26:14.420 the how the material is presented so that's a big problem in our in you know in how and how we teach

00:26:20.400 adolescence and you're right about wanting to do well wanting to be excellent wanting and being ambitious

00:26:26.300 which all the testosterone you know makes huge amounts of dopamine in the brain and so there's lots

00:26:32.660 of uh shall we say um seeking excitement so teen boys really want to seek excitement um sometimes to

00:26:41.780 the exclusion of caution but there's no excitement in the classroom generally for most teen boys all

00:26:46.800 right so the puberty the surge of testosterone reshapes the brain it's all it's priming it for

00:26:52.700 you know fatherhood basically but let's talk about before fatherhood because he had a chapter about what

00:26:58.000 happens to the male brain when a guy is in love so what what goes on when guy sees a girl falls head

00:27:05.660 over heels in love what's happening to his brain so you know if he's found someone that he feels

00:27:11.520 like is his his partner his match he's sexually attracted emotionally attracted and his whole

00:27:17.840 brain is like all of a sudden takes on every little bit of the things that she likes and how she is and

00:27:24.640 and he that we call it kind of an emerging of your two egos and that he kind of takes her into himself

00:27:30.760 in his own mind as as his love object and so he's um like they say head over heels he's head over heels

00:27:38.440 for her and um the dopamine is surging and the oxytocin the the love hormone starts to get going

00:27:46.820 because you know touching caressing kissing really releases lots of oxytocin in both male and female

00:27:52.200 brains so he has basically bonded with her and um it's almost some people describe it almost as being

00:27:59.960 uh psychotic because you have a whole different reality your reality is through the lens of her

00:28:05.880 everything everything has to do with her spending time with her what she likes uh etc etc so it's it's

00:28:13.680 quite um uh the whole male brain and body gets overtaken by love as the female does well i thought

00:28:21.180 it was interesting to you note that uh that men like there's like this sort of this idea that women

00:28:25.820 are more you know grow more attached and they're the more the quicker to fall in love but this research

00:28:30.620 shows that men actually fall in love faster than than women do and it's interesting because the 0.96

00:28:36.600 visual cortex you know that's that part of your brain that's back there at the you know at the base

00:28:40.780 of your skull right right on the top of your neck the visual cortex in males is very stimulated all the

00:28:46.600 time by testosterone and it's seeking out curvaceous females i mean and so if once he's found the one he's

00:28:54.620 he's he can have love at first sight much more easily yeah well and also so from a genetic

00:29:00.920 perspective from evolutionary sexual selection perspective uh there's this sort of idea that

00:29:05.860 the males of a species want to uh reproduce with as many females as possible because it increases the 0.78

00:29:11.840 chances of them spreading their seed but you highlight research that in some species and particularly in

00:29:16.820 humans that there is that but also there's some men or males who are predisposed to monogamy

00:29:23.740 what what happened what's going on there right so i think monogamy you know in our species there's a 1.00

00:29:29.620 wide variety between those males who tend to be primed to be to have many partners and those who are

00:29:36.240 primed to be monogamous and um uh i think it's also somewhat cultural um in that you know what what is

00:29:43.620 acceptable in your culture or not but there are so we think that that has to do something with both

00:29:49.880 testosterone level because the the varieties the testosterone level between 400 and a thousand

00:29:55.460 is a long range and that's adult males are in that range and males that are at the very top of that

00:30:02.660 uh testosterone range have a higher likelihood of being promiscuous and of having lots of mates

00:30:10.960 and those in the middle and in the lower end are tend have a greater tendency to be monogamous so

00:30:17.440 some of it may have to do with testosterone level some of it may have to do with culture

00:30:22.720 and some of it may have to do with that i talk about that vasoprestin receptor gene

00:30:27.540 in that there seem to be in the little prairie vole studies that we look at there's a vole that is

00:30:34.020 called the prairie vole and the males in that species are very monogamous they pair bond they take care of

00:30:41.600 the pups um and his cousin the montane vole is um just the opposite he's kind of a hit and run guy he's

00:30:50.380 very promiscuous and uh and inseminates many females doesn't do anything to take care of the pups 1.00

00:30:56.420 probably doesn't even know who his pups are so they're very different and they just they've discovered

00:31:00.560 that the vasopressin receptor gene which is another hormone in the brain in those um ones that are 1.00

00:31:07.280 monogamous are very a long receptor and the ones that are promiscuous are very short and humans have

00:31:13.640 that same kind of vasopressin receptor gene and in some males it's long and some males it's short

00:31:19.480 actually it's at 17 different lengths in humans so there's a very large range and some studies have

00:31:26.780 looked at that a big swedish study looked at that and found that the males that are have the longest

00:31:32.320 vasopressin receptor gene and would be hypothesized to be more monogamous actually have the

00:31:37.020 longest long-term marriages so there's something to do with genetics culture and and hormones all

00:31:44.300 wrapped up into that which i think that's just fascinating that we humans would have that type of

00:31:50.640 diversity and propensity that is really interesting okay so a guy falls in love all these hormones are

00:31:56.580 bathing his brain and his body to pair up with a female they do and a baby results right so when we 1.00

00:32:04.560 like what happens to a male the male brain when he he becomes a father so the fascinating thing about

00:32:11.540 the fatherhood hormones the testosterone drops by about 30 percent and then a hormone that we call

00:32:17.420 the parenting hormone both in males and females the prolactin hormone um in males goes up by about 25 or

00:32:24.920 30 so the males when they go into fatherhood it's not just the female body we know is changing like

00:32:32.240 mad she's going through pregnancy she has huge hormonal changes but it was a big discovery to find

00:32:37.060 out that the males have a whole fatherhood set of hormones which decreases their testosterone and

00:32:42.220 increases this parenting hormone called prolactin in males now prolactin you know the word pro

00:32:47.340 prolactin lactation means milk formation so not that males breastfeed and that is the hormone in

00:32:55.120 females that makes breast milk so we don't really know what that hormone prolactin is doing in males 1.00

00:33:01.220 but we think it probably has something to be doing with the the parenting hormone in males and does this

00:33:07.240 decrease in testosterone occur even before birth it starts to a little bit it starts to drop and then for

00:33:13.620 the first six months after birth um that's when it's noted to be um 30 percent down and then after

00:33:20.120 about six months it starts to climb back up to the the set point for that individual so interesting when

00:33:26.240 the infant is most in need of care from both parents um that testosterone level that might say

00:33:32.920 drive him some hypothesis says it might if it was still higher would drive him to maybe not stay as

00:33:38.420 close to home maybe drive him to seek out other partners and you know so um some of the thought

00:33:44.440 is it it basically decreases the sex drive in the male could it like couldn't the testosterone decrease

00:33:49.960 because like you're not sleeping right when i when i had my kid like for the first like six months

00:33:55.380 you'd like i hardly got any sleep and you know as you say testosterone most of it's produced you know

00:34:00.480 while you're asleep so maybe the kids crying keeping you up is reducing your testosterone so you stick

00:34:06.180 just be from total exhaustion which every parent i think the biggest deficit of every parent is sleep

00:34:12.300 please let me sleep right those babies they're decreasing your testosterone exactly they do the 1.00

00:34:17.540 babies decrease your testosterone so that you're correct so okay we've gone through puberty what 0.66

00:34:23.200 happens in adulthood is like you know from 30 to 50 do things kind of stay the same for men's

00:34:29.380 it's sort of a stable period so you know what the counterpart in females is you know females have 1.00

00:34:34.620 something called menopause at 50 where they just where their ovaries stop producing estrogen because

00:34:40.200 they've run out of eggs males never run out of sperm and so you guys continue to have production of sperm

00:34:47.040 and testosterone for your entire lives but it does decrease i think that the peak of male testosterone is

00:34:53.860 between the ages of 19 and 29 so that's when the sperm production is at its height and testosterone

00:35:00.220 production is at its height and then after about age 30 the um testosterone level starts to decrease

00:35:06.440 between like one and two or three percent per year so it just it goes down by about age 50 um males are

00:35:16.160 only producing about half of the testosterone that they produced at age like 25 i mean what happens to

00:35:24.580 the behavior because of that decrease in testosterone so about age 80 um the testosterone level has gone

00:35:30.900 down enough that i know that george bernard shaw always said oh yes thank goodness that i'm not being

00:35:36.540 driven by that anymore i think cicero said something like that too yeah so it's a it's a well-known

00:35:43.920 comment right of like men who have been sort of driven sexually all of their lives and that's not that

00:35:51.280 it's a negative thing but it's certainly something that sometimes it's not sometimes you wish that it

00:35:56.580 weren't there um and i think that so the what's called andropause is a gradual decline in testosterone

00:36:06.260 that's normal with male aging and um it's still plenty to to you know have to to have muscle strength

00:36:14.060 muscles and you know it's still plenty to have energy and some sex drive but not nearly the amount that

00:36:20.800 you had when you were 19 or 20 and i guess uh men start to mellow out a bit at this age as well

00:36:26.760 yeah and i think that that thing about seeing seeing others faces as being possibly aggressive and that

00:36:32.680 thing about being being more uh a sort of hair trigger to um you know i think the tendency to road

00:36:40.500 rage or the tendency to you know uh taking things wrong um and feeling aggressive about it that that

00:36:47.440 whole tendency uh starts to decrease yeah i mean it's something i when i've talked to my friends

00:36:52.580 for about the same age as me like 35 talking about the difference between our dads when we were kids

00:36:58.440 and then like them interacting with our our kids with their grandkids you know and i remember your

00:37:02.660 dads were sort of on edge right their work and like they're just kind of seem grumpy and you know

00:37:07.780 peevish right and then you know they're in their 60s and they just seem like a completely different

00:37:12.220 they're just like mellow and calm and just i know they seem like a happy puppy you know it's

00:37:17.840 very different and i think it's quite shocking to most all of us even the girls like to watch your

00:37:24.500 to watch your parents with your especially your fathers with your kids because you know they're just

00:37:29.840 like a big teddy bear yeah and i mean what do you think's happening so you you see a lot of men

00:37:34.700 older men these days starting to take trt testosterone replacement therapy i mean how is that going to

00:37:39.700 change things so you know so i'm kind of working on a new book called female brain 2.0 which is about

00:37:45.380 women age 50 to 100 plus and so a lot of the females i'm interviewing their husbands in their 50s are

00:37:52.800 taking testosterone replacement and uh it's quite interesting to talk with these this of course i'm

00:37:59.300 seeing it through the women's eyes and then talking of course to some of the men as well and

00:38:03.460 there's you probably see these ads on tv right that's called low do you have low t do you right

00:38:09.680 and so of course you have low t after the age of 50 or 60 it's supposed to be going down you're

00:38:16.180 supposed to becoming that big teddy bear grandpa you know that's that's the life stage you're

00:38:20.900 supposed to be at and indeed there are some men that medically um lose too much testosterone and

00:38:30.340 have such a little amount that they need to have a replacement but by and large medically

00:38:35.980 um this idea of low t would apply to every man going through his he's not going to have the

00:38:43.420 testosterone he had when he's 25 and um lots of men these days i think are finding it um i think maybe

00:38:51.320 it's also a very american phenomenon that you just don't you don't want to lose your edge right you

00:38:56.340 don't want to lose your edge and you don't want to lose your energy you don't want to lose your kind

00:39:00.880 of like um you know you're ambitious aggressive creative i mean whatever the edge is that you have

00:39:08.380 and so i think that it's kind of seeking the fountain of youth a bit that so your aunt the

00:39:14.700 answer to your question about what it's doing so the women i talk to are uh post-menopausal their 1.00

00:39:20.960 husbands are getting their testosterone injections and they know for the first two or three days

00:39:25.320 he's just going to want sex as much as possible at the age of 60 or 65 and they are really frankly

00:39:31.080 just not that interested it's not like they're never interested but not at that level so it does

00:39:38.240 cause some marital problems interesting and i mean i imagine too you know they're gonna if you take 0.99

00:39:43.380 you might lose that generative stage of your life right when you're old and you're kind of sealing up

00:39:48.380 your legacy like you might lose that because you're thinking you just have that edge again where you're

00:39:53.400 not the i don't know i guess nostalgic is the right word maybe i think the correct word you said

00:39:57.880 was generative there's that the word kind of generative in that you've reached a stage where

00:40:03.120 you may you may have done not everything you're going to have to do in your life but you've done

00:40:08.520 a huge amount already in your life and your and your your productivity and the things that you've

00:40:13.040 accomplished and um it's it's your turn to get to smell the roses a little bit but also to

00:40:19.660 kind of give back and mentor the younger generation so i think that that that urge to teach others and

00:40:27.720 become a mentor and become a wise wise elder um i think i think is a wonderful lovely thing for men

00:40:35.100 and if you're just completely putting your testosterone back up to where it was when you're 25

00:40:40.700 that you know you're creating a conflict in yourself between those two i agree with you i think it's it

00:40:47.360 becomes a conflict and um uh so you and i both have a you know i'm asking myself the question of

00:40:54.880 like okay i can see why they want to do that and they want to maintain their edge because there's a

00:41:00.940 feeling of the youth culture in our in the united states that if you aren't part of the youth culture

00:41:06.840 you're you're out of it you're you're cast off to the side so um you know i that that's something

00:41:13.200 that's it's it's something that every person goes through in their own change in identity and

00:41:19.760 development as we all get older and some people just aren't willing to let that happen i see a

00:41:25.520 future think piece in like the atlantic or something about this topic or something good i hope you write

00:41:30.580 it right well luann this has been a great conversation where can people go to learn more about your work

00:41:35.740 well they can go on either the male brain or the female brain i would say it's a fabulous place to start

00:41:41.500 because um as you noticed from the back of the book there's many many many um other articles that

00:41:47.120 it refers to and um they can just start to to pick all of those apart and do a deep dive into you know

00:41:56.040 what it means sort of biologically and emotionally to be male awesome well luann thank you so much your

00:42:00.860 time it's been an absolute pleasure likewise thank you for doing what you do we all appreciate your

00:42:05.540 giving voice to this this whole area of manliness thank you my guest it was dr luann brisendine she's

00:42:11.800 the author of the book the male brain it's available on amazon.com and bookstores everywhere you can

00:42:15.900 find out more information about her work on our show notes at aom.is male brain 0.98

00:42:20.660 well that wraps up another edition of the art of manliness podcast for more manly tips and advice

00:42:32.760 make sure to check out the art of manliness website at artofmanliness.com and if you enjoy

00:42:36.200 the podcast i've gotten something out of it i'd appreciate it if you take one minute to give

00:42:39.560 this review on itunes or stitcher it helps out a lot as always thank you for your continued support

00:42:44.040 until next time this is brett mckay telling you to stay manly

00:42:47.020 please

00:42:52.440 bye

00:42:53.660 my

00:43:01.960 why

The Art of Manliness - May 31, 2018

#410： The Male Brain

Episode Stats

Summary

Transcript