♪ >> from our studios in new york city, this is "charlie rose." charlie: we continue an exploration with -- of the human brain with a look at gender identity and the biology of the brain. gender identity is a person's subjective experience of their gender that may or may not correspond with the gender assigned at birth. the term transgender describes someone who feels his or her body and gender do not match. it is estimated that about 700,000 transgender people live in the united states. one joins me today sharing his

experience. again is a professor of euro biology at stanford university. he lived as barbara before he changed his sex to mail in 1997. we also have a group of scientists. i am pleased to have all of them here. we begin this conversation with my colleague eric. what are we going to talk about? eric: we are going to speak about gender identity and the biology of a -- of the brain. i like this topic because it shows how brain science can be a liberating influence in our life. as we understand the biology of our own gender identity better and become more comfortable with ourselves, we become more empathic to somebody else's gender identity. and we can understand if a

person says "i'm in the wrong body." we can sympathize with them. but this is not only an interesting topic, it is a timely topic. when you and i first began talking about this six months ago it was not on the radar screen. we were ahead of our time. but now you can take up an issue of the new york times or vanity fair and there will be a discussion of gender identity. charlie: 17 million people watched the diane sawyer interview. >> when we begin to speak about the biological underpinnings, we want to distinguish two different content ups -- concepts -- anatomical sex and gender

identity. anatomical sex is the body parts associated with sexuality and reproduction. gender identity is a more complex image that is a sense of self as a male, female or something else. let's begin with anatomical. this is determined by our genes. genes are ancient chromosomes. we have 23 pairs of chromosomes. we get half from our mother and half from our father. 22 of these are called otis soames and the differences between those that come from her mother and father are modest but they are profound. men are x x and women are x y. chromosomes are quite different from the order zones, and they have a different function from determining sex. let's deal with the y chromosome. we are born with

undifferentiated gonads that can move another -- move in either direction. they can develop into testes or ovaries. there is a sex determining region of y that activates a gene of the -- in the undifferentiated gonad into the taxis. if the y is not there, a female gonads develops. each of these have profound consequences. let's look at the testes. they develop in the first seven weeks of euro. -- euro. -- utero.\ this produces testosterone

responsible for giving you the male body form the brain characteristic of malfunctioning, as well as heavy aspects of your being. if this sex determining region lacks a why, you have development of an ovary. the ovary secretes estrogen and progesterone, which gives you the female body form and changes in the brain. these are extremely important changes. that's the easy part. this is the anatomical part. the more subtle and elaborate part is the gender identity. that's why we have brought together this spectacular group of people to talk about that. we have been with us -- ben with us. he is a long-term colleague. he is chairman of stanford and a

member of the national academy of science. he is a transgender person. he made a decision to undergo a body change, and he can tell us what it was like before when he felt like he was in the wrong body and how he feels now. people who knew him before can describe what it was like interacting with them as a woman, and now as a man. he is one of the pioneers in the united states -- scott is one of the pioneers in the united states of pediatrics area -- of pediatrics. he has adopted a european strategy and applied it in the united states of postponing puberty so people can think through what they actually want to do and make the decision in a thoughtful fashion. the reason he wants to delay puberty is once puberty forms it's a much more radical

procedure than if you receive it before puberty. we have catherine with us, she's interested in how sex is represented in the brain, and she has found in mice that in the male mouse there is a representation of the female. in the female, there is a reputation of the mail. this is a completely -- not a completely novel idea. floyd -- freud suggested we are all bisexual. he asserted that one side of sexuality matures, but the other remains. we have with us melissa hines, who is interested in how kids differ -- boys and girls -- in the gainsmes they play and how they interact with each other. he is -- she is interested in

how hormonal levels affect child's play. and we have janet hyde. she is interested in seeing one of the inferences and cognitive capabilities between men and women in computer science and mathematics and engineering. her data pretty much suggests that there is very little difference between them. as i have gotten to know her that her, i think that is incorrect. the more i speak to her she seems to have come to the conclusion that women are superior in mathematics. [laughter] anyway i think we are in for a fantastic program. charlie: let me begin with 10. -- ben. tell me the experience you went to -- the experiments you went through. -- the experience you went through. benl:: i think my experience was

typical for other transgender people. i was about four or five years old when i started to feel like a boy. i felt like a boy, i played with little boys, i preferred boys toys, i remember dreadfully wishing that i could be in the cub scouts and boy scouts. every halloween i would dress up as an army man or a football player erie it it also -- football player. it all seemed normal to me. as i got into middle school, i did start to feel more and more uncomfortable with this. i did not feel i should have breasts. i did not feel comfortable at all wearing dresses, makeup, jewelry and it became increasingly uncomfortable when i got into high school. i started to be teased more by kids. i had a lot of confusion about my gender and i felt ashamed of it. i never spoke with friends or family about it at all. charlie: no one.

ben: no. i felt ashamed and confused. don't forget that this is before the days of the internet. as i got into my 20's, i was doing well i was doing well in my career, i was doing medical training but i was increasingly uncomfortable and like many trans people i started to think about suicide but never actually attempted it. this is actually a picture of me back when i was barbara -- i think i was 30 at that point. i can still remember vividly even though that was 30 years ago, the agony that i felt. the discomfort putting on that dress, wearing jewelry, wearing makeup. anyway, i did complete my training and began my job at stanford when i was 40.

about two years and two that i actually developed breast cancer. i am still confused about my gender identity but i knew i did not like to have breasts. my doctor said i needed to do it must ectomy -- a must ectomy. -- a masectomy. i said, while you're there, can you take off the other breast. he agreed to remove the other breast, and i can't tell you how therapeutic that was. i felt relieved to have those breasts removed. i recognized that that was a very different response that my mom had when she had her must ectomy. she got it was a huge blow to her femininity. after the surgery, the doctor started talking to me about reconstructing the breasts and i was horrified. there is no way you are putting those things back on me. it increasingly include --

occurred to me that there was something about my gender. i was reading the san francisco chronicle one day later when i was reading about an openly female to male transgender person in the bay area. i realized for the first time in my life that there were other people who had experienced the same sorts of gender confusion. there were other people like me and i might be cringe gender. -- transgender. i want to see a psychologist at stanford who ran a gender clinic. after they evaluated me, they thought i was transgender, and offer maybe possibility of changing micex, which was immediately irresistible to me. in the coming weeks, i decided to change micex. i had already had the must ectomy's -- the upper surgery, but i did not want to do the lower surgery. all i had to do was take testosterone, and you can see the effects it has had on me. it's powerful stuff. the most surprising effects

about the testosterone was that it became much harder for me to cry. male to female's report that it now becomes much easier, so that was perhaps a surprising experience. i felt after i changed sex -- it's hard to describe the intense relief that i felt. i have been so much happier since. i have never had another suicidal thoughts. -- suicidal thought. at the time, i have been a scientist at stanford for several years, and was worried that changing sex with heart my career. this was 20 years ago. i have to say that all of my colleagues, friends, and family were supported, and i have fortunate -- i have been fortunate to have my career continue and have wonderful students. the other thing i would like to say is, i think the other

surprises that i found that living as a man has dramatically changed the way people react to me. i can tell you a story about an experience that happened to me shortly after i changed sex. a couple of years later i decided to give a seminar, and one of my friends told me that after i gave the seminar one of his colleagues was talking to him about it, and he said, gee, his work is so much better than his sisters. -- sister's. [laughter] i think that points out something -- all of us trans people have lived our life has both genders, and we all share an intense anger at the different ways that society treats men and women based on their gender. i think in general we would all say that society -- a man

assumes they are confident until proven otherwise, -- competent until proven otherwise, and women are considered incompetent until proven otherwise. i have devoted part of my time to try to help women in their careers. charlie: let me turn to norman. listening to that story, i think it may be typical for someone to go from questioning to looking to solutions to the reaction after you've change -- what does this say about gender identity? norman: i wish we knew more. i want to show you a powerful example of identical twins who in this case, one of the male twins and we have proven that these twins are indeed identical and born male, but one of them

at age three started to say everything about being a girl. in fact if there was any issue that came up she turned it into an issue of gender. she did some of those things that we consider hallmarks like preferring to wear female underwear and pajamas, etc. by the age of seven, the family decided with the help of a counselor to change her name to a female name and to have the child assume a female role. here is twin sister with twin brother at the age of just about nine to 10 years of age. they were in fourth grade.

what i want to point out is if i switched all the attachments to them, the airings, the clothing the hairstyles, the shoes, you could basically switch one to the other. the fact of the matter is that kids with their clothes on our virtually interchangeable pre-puberty. actually their hormonal levels are virtually, at that particular point interchangeable. everything happens really at puberty. here they are at age 14. because it is so difficult to live in a gender different from your biological sex, when you have the toxic effects of your genetically home on -- hormone driven puberty which would make twin sister look exactly like twin brother.

you can see that she looks still almost like a nine or 10-year-old, and there is a good reason. she has had her. very -- her puberty suppressed. as the next slide shows, the hormone levels across the human lifespan. look at the blue line, the male levels of testosterone. during fetal life, the level of testosterone in the fetus rises to a level close to the full adult range. and then it falls, and then there is another blip up right after birth, the kind of second puberty, then things go completely dormant. in fact, if they didn't go dormant, we would have a bunch of puberty -- pubertal looking fifth-graders running around because everything is suppressed. >> when we think about possible

causes for transgender, wouldn't it be possible that some aberration in testosterone or estrogen secretion might be one of the contributing factors? norman:it's possible. it's a dynamic stage. we still don't know what that bump is after birth, but what role it plays, or boys that are born without testes but are otherwise normal showing differences as a result of that. the problem is, if we want to look at a hormone we have to get to to out and measure it. you can't get it out of the brain. the other problem is sometimes it isn't the hormone level that is important, but the affinity of the receptor for the hormone. it is difficult to measure such things.

>> it's a fascinating biology problem to see the underpinning of transgender identity because as you point out it's so important, because kids who are in the wrong sex a suicide attempt is very serious. charlie: it is one of the highest risks of any -- eric: it is something we need to understand. norman:andy pubertal process reawakens again. the system that had been awakened in euro -- in utero comes back . it causes the release of other hormones that strike the ovaries are testes and causes the release of what we call sex steroid hormones -- testosterone and estrogen, and those produced the difference between the body of the male and female associated with puberty. we have been able to probably

since the 1980's -- we have been able to block the release of the hormone from the hypothalamus to the pituitary and once you do that so far upstream everything downstream goes down to zero. we have a record of this medication being completely successful in shutting them down until the appropriate time. also, the fact that it is completely reversible. look how revealing this is because the twin sister affirms a female identity and then puberty goes on for two years, two years to get more time for counseling without the pressure for body change. that is important, because if we give or estrogen, that is going to have terminated effects. take a look at what would have happened to her if she had not been given this blockade. she would look exactly like twin brother. he is in early puberty for a 14-year-old, but so would she

have been, because they are identical. here are the twins at age 17. at age 14, just after that picture was taken, she began estrogen. while at the same time having her male hormones blocked. with that, our patients don't need breast surgery when they feminize. it is so effective. in that picture she is entering her junior year of high school as is her brother, and she is fabulous. this past october, the dutch reported the first follow-up of the patients -- 55 of whom had puberty blocked and his sex had switched in the matter of our twin sister. the dutch had puberty at 16.

and the uncomfortableness of their gender disappeared. the dutch found that kids treating this way were psycho socially functioning as well or better than the control group of non-transgender kids they were being compared to. the dutch gave me their protocol in 2006. we started using it in boston children's hospital, which at the time we were the only major medical center to do so but there have not been that many years since 2006, and over 40 programs now -- so it's now becoming the standard of care. ♪

♪ charlie: let me turn to catherine and talk about whether this is wired. catherine: we have just heard from ben and norman that fumes -- humans have fairly -- very early and strong senses of their gender identity. in animals as in humans, males and females display clear differences in behaviors. most of fleet -- mostly but not exclusively related to social behaviors. males and females have very distinct sexual and aggressive displays, and we have seen in the previous episode that

females are usually maternal and males are attacking the cubs. how are these differences established and maintained? the basic mechanism cannot be studied at in humans, so instead my laboratory is using the mouse as a model system. mice display clear differences in gender specific behaviors. bring control in mice can be studied using the powerful tools of molecular neuroscience and genetics. sex typical behaviors, particularly aggressive and parental behavior, are extremely maintained across different animal species, so the brain

control of those behaviors is also very maintained across animals. in contrast the signals that trigger these behaviors are usually extremely specific of a given species. for example, in the species of birds called the american flicker, there is only one sign that matters and terms of gender specific behavior. that is the black mustache on the mail. if you remove the black mustache from the meale, then the other males will attempt to copulate with the male without the mustache, because they will assume it is female. if you paid to the mustache on the female, the males will attack that mustache. if i have a mustache, i may mail -- i am a male, if i don't, i am

a female. we use olfactory tools called pheromones, and humans are particularly sensitive to visual and auditory cues, a fact that has been exploited specific -- effectively. once we know the signals that trigger gender specific behavior, now we can look into the brain. how is the brain processing the signals in establishing these general specific -- gender specific behaviors? as we have heard young males have a rapid release of testosterone, and this release has been shown to be absolutely essential to masculinized the brain. in contrast, females do not have this release, so in males, testosterone is essential to

establish and maintain the very specific set of circuits underlying male specific behavior, and females organize their brain in a different way. to control female specific behavior. in our lab, we have done a number of genetic experiments that have shown that the situation is a little bit more complex. the experiment we did is actually very simple. we look at new events for pheromone detection, which is indicated by this little crosshair on the structure of the brain. this animal is insensitive to sex specific cues.

when we look at their behavior we saw something surprising. in grey is female, in black is male. the female is mounting the male which is a very male specific sexual display. this female is displaying the male specific behavior. this male strangely instead of attacking pups is now retreating an infant and bringing it to the nest the male has. this mouse is displaying female specific parental behavior. so, what do we learn? what we learned is that the brain of both males and females contain the right presentation of male and female behaviors. the male is repressed by pheromonal system. the female specific circuit is repressed. what is happening is the repression of the opposite brain, opposite sex behavior circuit no longer exists and therefore the female is able to display both male specific

behavior and female specific behavior. similarly, the male can display both female and male specific behavior. eric: i think this is so beautiful because it provides the way we can begin thinking

and exploring transgender identity if we have the circuits. you can see how it can contribute to wanting to be another gender. i think this is very profound. catherine: exactly, as eric mentioned, this shows the brain of males and females are similar. and specific hormonal and genetic regulation leads to the predominate but not exclusive display of the behaviors of given sex. this is extremely important because animals occasionally need to display the behavior of the other sex. we have seen in the previous

episode that males are occasionally ok to display parental behaviors. in many species, females are using mounting as a sign of dominance. the brai has been shownn to be bisexual in fish, in reptiles more recently and now in mice. we think this ability to have the both presentations of the male and female brain could be totally relevant to gender identity. charlie: let me turn to melissa and talk about defining gender identity and sexual orientation and gender behavior. melissa: i study the role of testosterone and human development. we studied genetic conditions that cause people to have either higher or lower levels of testosterone during prenatal development than would otherwise be the case. from those people, evidence suggests testosterone in human also influences gender development, including gender identity. to start, it is useful to put this into context to expand our understanding of the dimensions of gender related behavior. we have talked about anatomical sex and gender identity which is our sense of self as male or female or something else. also, people have sexual orientation and this is separate to gender identity. it refers to our erotic interest in male, females, both or neither.

finally, there is a third class of peter called gender role behavior. these other characteristics that differ on the average. some are different from others. some of the biggest ones are seen in childhood toy preferences. the next image shows the sex difference in height and we are all familiar with this. males tend to be taller than females but there is some overlap. the males are the blue and the females are the orange. the overlap would be the people that you would not know their gender by knowing their height. the next image shows these gender differences in play play with toys like vehicles or boys toys or dolls, are similar in size to the sex different height. finally, we see the gender difference in identifying with the male gender.

we can see this gender difference is even bigger and there is almost no overlap between males and females, but there are some people who are in the other distribution. these include people who want to change their gender. how does this come to be? we have talked about these sex differences in testosterone, some of which occur very early in life. this corresponds to a period very rapid brain development so it provides an opportunity for hormones to program the brain in ways that might have enduring influences across the lifespan including gender identification. the next image shows data about women who have had very high level of testosterone's before e before birth.

about 2% of women who had very high testosterone, in adulthood decide to live is men. it is hundreds of times more than would otherwise do so. this has increased many times over by being exposed to high testosterone prenatally. the next image shows men. in this case xy individuals who are actually xy females because their cells cannot respond to testosterone. they have test these they are tes, they are producing testosterone, but because their cells cannot respond, they look like girls. almost 99.9% of them want to live as women. eric: it is so profound because although we don't know the vast majority of cases what causes

the desire to change sex, here we find one concrete biological te biological explanation. it is clearly a biological factor and with time we will be able to identify the significant number of other ones. i think having one example is good. melissa: when i began this work people thought these different interests in boys and girls were completely socially determined but it turns out these are altered by prenatal testosterone exposure. the next slide shows the toy choices of girls and boys in general versus those exposed to testosterone before birth. boys spent most of their time playing with toys like vehicles. girls spent most of their time playing with toys like dolls. the girls exposed to testosterone prenatally or in between. they spend about half their time playing with toys that boys normally choose and about 30% of their time playing with toys that girls normally choose.

these are different dimensions of behavior. the influence on gender identity is less powerful, it appears then the influence of testosterone on childhood play. that leaves a lot of unidentified factors that contribute to gender identity outcomes. finally, this is not just testosterone acting on the brain before birth, but also children who have high levels of testosterone engage in different behaviors and this has a feedback aspect on their brain developed. this becomes an increasing mechanism where their behavior is increasingly masculinized as they go through life. charlie: thank you. janet, talk about cognitive abilities and performance. janet: we have lots of stereotypes in our culture that there are gender differences and abilities. people believe that boys are

better at math and girls and women are better at verbal skills and boys are better at spatial performance. what does the real data show? we are at distributions for male and female performance, blue for male and orange for females. you see the most recent data shows that girls are tied with boys in mathematic performance. many people find this surprising but i have data for millions of people showing this. in regards to verbal performance, you can see there is a female advantage but it is tiny. you can hardly see it. these are very subtle, slight differences. for spatial performance, the difference is a little larger favoring males. i will show you one spatial performance that involves the ability to rotate three-dimensional objects. other kinds of spatial performance do not show this quite a larger difference.

you need this spatial ability if you need to be an engineer or architect or if you want tonight navigate around new york city. we get this gender difference in spatial performance in the absence of the spatial curriculum in the school. we teach kids lots of verbal skills and mathematical skills. we don't teach them spatial skills. these are completely trainable. some school districts are getting the message and starting to institute these programs. if we want to do something to foster women getting into areas like engineering where they are very underrepresented, instituting a spatial curriculum might really do a lot to help. i also want to emphasize the importance of cultural context in shaping these gender differences.

this is the percentage of phd's awarded to women in the u.s. by decade beginning in the 1890's. it turns out, i did not know this, it turns out even in the 1890's, 11% of the phd's were going to women. you can see it inches up in the 1930's and the percentage plummets in the 1950's. only 5% of the phd's are going to limit. it has been inching up ever since. today, 31% of the phd's in mathematics are going to women. why didn't plummet in the 50's? the men came home from the war and the women were delighted to see them. they went to the suburbs and had lots of babies. there is not one single biological force that causes women to be good enough to get a phd. it has much more to do with coulter will context. cultural context. it is findings like these that led me to propose the

principle of gender similarities. men and female are similar in most biological performances. you saw math performances which is stereotyped. there are performances for women in those careers. this map shows the gender similarity type is. we have the overlapping distributions. you can see there is huge overlap in which males and females are similar. let me look at psychological disorders because for some disorders we do get very lopsided gender ratios. on the left part of this graph you can see two disorders were many more men are affected. alcoholism and autism.

the blue bar is the preponderance of males. that is not to say we don't have women alcoholics or girls with autism, but it is a preponderance of males. on the right, you can see depression and the eating disorder of anorexia -- it is a preponderance of women shown in the orange bars. we do have these lopsided gender ratios. we wonder why those are. my research has been on gender differences and depression. the gender difference in depression is not present in childhood, but it begins to emerge between 13 and 16 years of age as you can see the orange bar is going up. it widens between 15 and 18 years of age.

gender differences in depression emerges in adolescence. ♪

charlie: let me go back to this idea of how society is responding because we know from the cover of "vanity fair," we know time magazine did a cover story which i am told is the second-biggest selling "time" magazine cover story that year with the one exception of the pope. transgender is right behind the pope.

[laughter] >> it is unfortunate society often sees transgender to be a mental illness or an immoral choice. transgender people are still denied basic human rights, often subject to violence. ben: transgender people can still be fired just for being transgender. as we heard today, the brain has innate circuits that determine our gender identity. to be transgender is not a choice i made, but it is how i was born. i should mention something we have not really brought out yet,

there is a broad spectrum of transgender people. some of them prefer not to change sex or even to be identified as male or female. for some of us, there is a compelling innate need to change sex. 40% of us attempt suicide. i think by helping transgender teens to avoid this agony, the dutch pioneers are great. >> you are advising your students at stanford, right? what is it you can provide? ben: in recent years catherine,i have been amazed at how many young lgbt, lesbian gay,bisexual, transgender students,trainees and young scientists are reaching out to me. every time i visit another university to give a talk, i often get e-mails in advance from young kids often still in the closet and very concerned about whether coming out will ruin their careers. they want to meet with me and talk about this. i always advise them to be open

and live openly as who they are. people are very, very accepting today. there will be a few ignorant people, but never let other people define who you are. charlie: so, what should parents do? eric: i think the first thing parents should do is sit down and take a deep breath. [laughter] norman: and realize that the prepubertal child is in a state of exploration. it is no accident that both boys and girls go to the boy toys and girl toys in kindergarten.

this is not gender identity expression by in large. this is almost always a gender roleplay which is normal for children. now, of children who are fairly persistent in their cross-gender play, but are prepubertal, only about 20% to want to be transgender. 80% are not going to be transgender. what i would say to parents is that if your child is getting close to puberty or worse is already in puberty and is showing this kind of behavior, particularly underwear wearing and saying i'm the wrong gender, etc., then you need to get help for that child fast. that maybe calling your pediatrician and asking for a gender specialist to meet with your child because a child who is, according to the dutch and us, a child who holds on to the belief that they are in the wrong body on the outset of puberty -- it is like pinocchio becoming a donkey -- they will take their life.

these are the kids who are the real deal. charlie: over the series of three years, you and i found a range of things we have traced to the brain and understood. in some cases, what we understood about what was taking place inside the brain was large and some small. where do you put this in terms of understanding what is going on? eric: i think we are in the very early stages of understanding. this discussion points out there is a biology. it is a challenging problem. but, our understanding is very modest. we talked about this before. many times people a vas how have asked how long it will take until we have a satisfactory understanding of the brain. it will take a century. we have made a lot of progress in the last few years that we are long way.

>> gender identity is so essential to who we are and our ability to be happy. we have a duty to provide some kind of explanation. catherine: it is not all black and white. ben: differences are not disorders. i'm proud to be transgender. i think it has different innovations and perspectives. the real question is why society persists in insisting that male brains are better brains which we have heard tonight is definitely not the case. eric: one thing that is interesting to see is as you function in a way that you are comfortable with -- as an does it increase your creativity? ben: and released a lot of mental energy that was devoted to confusion.

i would say yes. i have felt much happier and productive as a person. charlie: what percentage of people go under anatomical change? norman: we are in a state of flux on an operation that could cost a lot of money. the reason i say that is because insurance companies are waking up to the idea that this is a medical condition. that it is entitled to be billable for surgical and

medical aspects of their care can be covered by insurance. it is going to change everything. up until now, people had to save up to have the surgery. it starts from the top down. first, you have to not make it as a mental illness. you have to define it as a physical problem which it is. hiding it as being gay was what freed up people starting to see gay people is not having a psychiatric illness. it was having it removed from the manual of mental illnesses. we will see. the colleges that are self-insured, maybe even the college you went to, his paid by people. if i am going over to some of them and seeing them. charlie: i thank each of you very much for coming. there is enormous interest, as

you can see in the publications and also the conversation that is taking place. this subject was introduced in terms of a television program -- somebody came up to me and identified themselves as transgender. but, they said that to me that the fact it has gained so much attention made all the difference in their life. they felt not so isolated and not so different. they felt like they had been identified so they can have an appreciation of where they stood and what their options were. what are we doing next time? eric: we will continue to discuss child development. what of the consequences of growing up under different circumstances? how does it affect the cognitive development of children and is a passed on from generation to generation? charlie: thank you. thank all of you. and thank you. we will see you next time.

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>> ♪ at the hop ♪ little anthony: hi, i'm little anthony from little anthony and