1 00:00:06,171 --> 00:00:09,402 It's the most fundamental act of human life. 2 00:00:11,643 --> 00:00:15,079 And though we may have come a long way from our early ancestors, 3 00:00:15,214 --> 00:00:18,183 one thing hasn't changed much. 4 00:00:20,119 --> 00:00:21,108 Sex. 5 00:00:22,554 --> 00:00:24,579 Yet, despite being widely practiced, 6 00:00:24,723 --> 00:00:27,283 sex has always been a bit of a mystery. 7 00:00:27,893 --> 00:00:30,384 But science is starting to unlock its secrets 8 00:00:30,529 --> 00:00:35,398 literally getting under our skin to reveal a new, bizarre world. 9 00:00:39,471 --> 00:00:42,736 A world where the truly unexpected can happen. 10 00:00:45,144 --> 00:00:46,771 For the first time on television, 11 00:00:46,912 --> 00:00:49,972 we follow a woman under the influence of hormones, 12 00:00:50,115 --> 00:00:51,275 acquiring the body, 13 00:00:51,417 --> 00:00:54,716 the mind and facial hair of a man. 14 00:00:58,424 --> 00:01:04,124 Understanding sex is the key to understanding how to build a human. 15 00:01:30,089 --> 00:01:31,750 All humans are built in bits, 16 00:01:31,890 --> 00:01:34,450 far too small to be seen with the naked eye. 17 00:01:35,761 --> 00:01:36,955 We're made up of cells. 18 00:01:39,898 --> 00:01:46,531 And inside every cell is exactly the same mix of genes - our DNA. 19 00:01:48,240 --> 00:01:52,006 Until recently, reproduction was regarded as pretty straightforward. 20 00:01:52,344 --> 00:01:55,575 To build a new human you first take the genes that make up a woman, 21 00:01:55,881 --> 00:01:57,746 then the genes that make up a man, 22 00:01:57,883 --> 00:02:00,716 and then enthusiastically mix them up. 23 00:02:01,887 --> 00:02:03,980 But things aren't quite that simple. 24 00:02:05,023 --> 00:02:07,457 We might have been doing it since the dawn of time, 25 00:02:07,593 --> 00:02:11,154 but scientists know very little about the basic processes. 26 00:02:20,606 --> 00:02:23,268 Reproductive physiologist Doctor Roy Levin, 27 00:02:23,408 --> 00:02:27,936 has struggled with the technical limitations of studying sex for decades. 28 00:02:28,313 --> 00:02:31,305 We didn't really have the apparatus to allow us to do the measurements. 29 00:02:31,450 --> 00:02:33,418 And there was a long period of time 30 00:02:33,552 --> 00:02:35,486 when you only guessed what was happening 31 00:02:35,621 --> 00:02:39,182 from the external appearances of men and women in coitus. 32 00:02:39,324 --> 00:02:41,349 So that you couldn't really tell what was happening inside, 33 00:02:41,493 --> 00:02:42,460 because you just can't see. 34 00:02:43,962 --> 00:02:46,522 Cur understanding of sex hasn't moved on much 35 00:02:46,665 --> 00:02:49,657 since Leonardo Da Vinci first started dissecting corpses 36 00:02:49,801 --> 00:02:52,326 and studying them over 500 years ago. 37 00:02:53,772 --> 00:02:58,175 The Queen holds this drawing by Leonardo in her very own private collection. 38 00:03:04,917 --> 00:03:06,976 Doctor Levin's life-long quest to reveal 39 00:03:07,119 --> 00:03:10,213 the secrets of sex is taking him to Germany. 40 00:03:11,790 --> 00:03:13,382 What I've come for is a machine. 41 00:03:13,625 --> 00:03:16,116 This is a machine that makes the body transparent. 42 00:03:16,261 --> 00:03:18,092 You can look inside and see movements 43 00:03:18,230 --> 00:03:22,132 and the secrets really of coitus and how people get sexually aroused. 44 00:03:22,267 --> 00:03:24,633 There are very few machines like this in the world, 45 00:03:24,770 --> 00:03:27,295 and one of them is here in a town called Krefeld, 46 00:03:27,439 --> 00:03:30,101 quite a few miles outside of Dusseldorf. 47 00:03:31,543 --> 00:03:36,674 And the machine Doctor Levin's come to see is this FMRI scanner. 48 00:03:38,217 --> 00:03:39,707 It's basically a camera which uses 49 00:03:39,851 --> 00:03:43,082 magnetic fields to penetrate human flesh. 50 00:03:44,923 --> 00:03:47,153 Today, in the interests of science, 51 00:03:47,292 --> 00:03:49,817 Michael DeGroot and his girlfriend Liz Leahy 52 00:03:49,962 --> 00:03:53,989 are going to attempt to have sex in its cramped confines. 53 00:03:55,601 --> 00:03:57,159 Well, this is the machine as you can see inside, 54 00:03:57,302 --> 00:04:00,032 it's got, like, two doughnuts, those are the very magnets, 55 00:04:00,172 --> 00:04:01,503 and in between is the space 56 00:04:01,640 --> 00:04:03,665 that you'll lie down in and have coitus. 57 00:04:03,809 --> 00:04:05,174 So it's been specially adapted, 58 00:04:05,310 --> 00:04:06,834 that means just a single board has been put down, 59 00:04:06,979 --> 00:04:08,913 and you'll lay in between the two magnets, 60 00:04:09,047 --> 00:04:10,071 and hopefully that will capture 61 00:04:10,215 --> 00:04:13,480 the images of what's going on during sexual intercourse. 62 00:04:13,619 --> 00:04:15,211 The other thing that has to happen is, 63 00:04:15,354 --> 00:04:17,447 Liz, is that you have to wear this girdle 64 00:04:17,589 --> 00:04:18,681 it won't do much for your figure, 65 00:04:18,824 --> 00:04:20,519 but it'll hopefully capture the images 66 00:04:20,659 --> 00:04:22,183 from what's happening inside your body. 67 00:04:22,327 --> 00:04:24,090 So you have to put this sort of around you, 68 00:04:24,229 --> 00:04:26,959 in the pelvic area, and then you lay on top of that. 69 00:04:27,099 --> 00:04:29,727 And so that's really basically all there is to it. 70 00:04:29,868 --> 00:04:31,233 The other thing is though, Michael, 71 00:04:31,370 --> 00:04:36,831 that we'll help you to perform with this pharmaceutical support for it. 72 00:04:36,975 --> 00:04:38,567 So hopefully, it'll help you to do this. 73 00:04:38,710 --> 00:04:40,473 So let's go and get changed. Okay? 74 00:04:40,612 --> 00:04:41,203 Okay. 75 00:04:41,747 --> 00:04:43,772 Doctor Levin is well aware of the problems 76 00:04:43,915 --> 00:04:45,439 that need to be overcome 77 00:04:45,584 --> 00:04:47,848 if this experiment is to be successful. 78 00:04:48,153 --> 00:04:51,122 It's not the easiest thing in the world to maintain an erection 79 00:04:51,256 --> 00:04:56,216 and have intercourse in terms of this particular set-up. 80 00:04:56,361 --> 00:04:58,886 They're brave people that go into these machines. 81 00:04:59,031 --> 00:05:00,157 We've seen the machine, 82 00:05:00,299 --> 00:05:02,460 and I'm interested to see how we're 83 00:05:02,601 --> 00:05:03,966 going to manoeuvre ourselves in there, 84 00:05:04,102 --> 00:05:06,036 because it looks like a pretty constricted space. 85 00:05:06,171 --> 00:05:09,572 And I know they want us in one certain position. 86 00:05:09,708 --> 00:05:13,610 So I hope - I hope that that we're able to situate ourselves 87 00:05:13,745 --> 00:05:15,235 so that they get the images that they want. 88 00:05:15,380 --> 00:05:17,245 I'm just -that's my main concern. 89 00:05:18,517 --> 00:05:22,009 Michael has a personal interest in taking part in this study. 90 00:05:22,721 --> 00:05:25,622 I have a small background in human sexuality, 91 00:05:25,757 --> 00:05:26,883 in the psychology aspect, 92 00:05:27,025 --> 00:05:28,822 because I'm a psychology under-graduate. 93 00:05:28,960 --> 00:05:31,724 So with my background I just kind of got an interest, 94 00:05:31,863 --> 00:05:34,559 and hearing about these images that would be one of the first times 95 00:05:34,700 --> 00:05:35,758 that these would ever be recorded, 96 00:05:35,901 --> 00:05:39,064 I just thought it would be really fun to be a part of this work. 97 00:05:43,875 --> 00:05:45,240 Okay, we're ready to go. 98 00:05:45,377 --> 00:05:46,571 You can start now. 99 00:05:54,319 --> 00:05:57,379 The scanner takes a picture every three seconds, 100 00:05:57,522 --> 00:06:01,219 and produces images of the body from top to bottom. 101 00:06:02,127 --> 00:06:04,095 This is the first time that such images 102 00:06:04,229 --> 00:06:06,424 have been seen on British television. 103 00:06:08,400 --> 00:06:09,867 You can sort of see the penis here. 104 00:06:10,001 --> 00:06:12,128 That's outside of the body from about here. 105 00:06:12,270 --> 00:06:14,500 And this is the root of the penis inside the body. 106 00:06:14,639 --> 00:06:16,334 And this is inside the female's body. 107 00:06:16,475 --> 00:06:17,942 That's her pubic symphysis, the bone, 108 00:06:18,076 --> 00:06:20,340 and here would be the pubic hair just around here. 109 00:06:20,479 --> 00:06:21,605 That's, of course, her bottom. 110 00:06:21,747 --> 00:06:23,908 And this is the vagina that the penis is in. 111 00:06:24,049 --> 00:06:25,516 And at the top here is the glans. 112 00:06:25,884 --> 00:06:27,909 And the thing that's obvious in this cross-section 113 00:06:28,053 --> 00:06:31,216 is the unusual shape of the penis during intercourse. 114 00:06:31,356 --> 00:06:32,288 Well, it's like a boomerang. 115 00:06:32,424 --> 00:06:34,449 That's what we've found out by this machines actually, 116 00:06:34,593 --> 00:06:37,391 that, in fact, the penis does look like a boomerang. 117 00:06:37,529 --> 00:06:40,862 It isn't straight like they drew it in the early times. 118 00:06:40,999 --> 00:06:44,935 In fact, it is bent, as you can see quite clearly. 119 00:06:45,070 --> 00:06:46,332 It's actually incredible, 120 00:06:46,471 --> 00:06:50,271 because as far as when you have an erection you think it's, 121 00:06:50,409 --> 00:06:54,209 you know, hard and solid as a rock or wood or something, 122 00:06:54,346 --> 00:06:56,610 but when you look at those pictures it's unbelievable, 123 00:06:56,748 --> 00:06:58,147 like, you have the 90 degree angle, 124 00:06:58,283 --> 00:07:00,808 and you can't even imagine that it would bend that way. So... 125 00:07:00,952 --> 00:07:02,647 It's really fascinating to see what the body does. 126 00:07:02,788 --> 00:07:03,618 Just incredible. Yeah. 127 00:07:03,755 --> 00:07:05,313 It's not something you really think about 128 00:07:05,457 --> 00:07:07,084 when you're actually in an act like that, 129 00:07:07,225 --> 00:07:09,250 and to actually have the pictures to see what's going on, 130 00:07:09,394 --> 00:07:10,884 it's just extremely interesting. 131 00:07:12,230 --> 00:07:13,891 Nobody knows why the penis has to 132 00:07:14,032 --> 00:07:17,126 go through extraordinary contortions. 133 00:07:17,436 --> 00:07:19,870 One theory is that it's a relic from our past, 134 00:07:20,005 --> 00:07:24,499 when sex was more commonly done on all fours and not face to face. 135 00:07:27,245 --> 00:07:29,213 Doctor Levin is aware these experiments 136 00:07:29,347 --> 00:07:31,679 might be seen as prurient or trivial. 137 00:07:33,218 --> 00:07:35,982 But he believes that understanding the mechanics 138 00:07:36,121 --> 00:07:38,817 has important practical applications. 139 00:07:38,957 --> 00:07:41,517 One possibility is that when we get a bank 140 00:07:41,660 --> 00:07:44,151 of normal images of functional 141 00:07:44,296 --> 00:07:47,265 the normal reproduction and the movements that occur, 142 00:07:47,399 --> 00:07:48,991 and we have a whole range of images, 143 00:07:49,134 --> 00:07:50,999 because this is just one couple that we've done, 144 00:07:51,136 --> 00:07:54,731 we can then possibly look at people who are abnormal, 145 00:07:54,873 --> 00:07:56,500 that they can't have children perhaps, 146 00:07:56,641 --> 00:08:00,372 and their -the dysfunctions that are there might be in the movements, 147 00:08:00,512 --> 00:08:02,810 might be in the motility that we can pick up, 148 00:08:02,948 --> 00:08:04,245 and then we'll be able to look at that 149 00:08:04,382 --> 00:08:05,508 and possibly have treatments for it. 150 00:08:05,650 --> 00:08:07,015 But that's really looking into the future. 151 00:08:07,152 --> 00:08:10,519 We¡¯re just starting out really, the first step this is. 152 00:08:12,057 --> 00:08:14,116 Understanding anatomy is important 153 00:08:14,259 --> 00:08:18,025 if you really want to understand what makes men and women tick. 154 00:08:19,197 --> 00:08:22,360 But there's also much that can be learnt by studying their cells. 155 00:08:23,768 --> 00:08:27,397 Down at this level, men and women are all very similar. 156 00:08:28,106 --> 00:08:32,338 Each cell holds a nucleus which, in turn, contains DNA, 157 00:08:32,577 --> 00:08:34,101 the substance that builds us. 158 00:08:35,647 --> 00:08:39,014 Each cell contains over two metres of DNA, 159 00:08:39,251 --> 00:08:41,947 divided and packaged neatly into chromosomes. 160 00:08:42,587 --> 00:08:44,452 There are 46 of these. 161 00:08:47,058 --> 00:08:49,686 The real difference between men and women is 162 00:08:49,828 --> 00:08:53,457 that women normally have two X sex chromosomes, 163 00:08:54,533 --> 00:08:58,629 while men have an X and a Y. 164 00:09:00,472 --> 00:09:02,702 But it's not always that straightforward. 165 00:09:06,945 --> 00:09:08,242 Look at Jan Johnson. 166 00:09:08,713 --> 00:09:11,648 She's an athletic, feminine 42 year old woman. 167 00:09:12,417 --> 00:09:14,647 She's also six foot three inches tall, 168 00:09:15,053 --> 00:09:17,783 a distinct advantage when you're playing volley-ball. 169 00:09:19,057 --> 00:09:23,289 The other thing that's different about Jan is that she's genetically male. 170 00:09:24,629 --> 00:09:28,497 There's a huge stigma attached to my condition. 171 00:09:28,633 --> 00:09:32,125 I think a lot of people don't want to talk about their personal conditions, 172 00:09:32,270 --> 00:09:34,761 and, you know, no one's perfect. 173 00:09:34,906 --> 00:09:37,067 People - lots of people have problems, 174 00:09:37,208 --> 00:09:42,168 and it just - it's a matter of facing your deepest, 175 00:09:42,314 --> 00:09:45,613 darkest secrets and bringing them out in the open. 176 00:09:46,985 --> 00:09:49,283 She had no idea that there was anything strange 177 00:09:49,421 --> 00:09:50,979 about her when she was growing up. 178 00:09:52,057 --> 00:09:57,051 The only thing that I remember is that I was just very active, 179 00:09:57,195 --> 00:09:59,561 and I just had a lot of energy. 180 00:09:59,698 --> 00:10:02,895 In terms of, like, feeling different no, I didn't. 181 00:10:03,034 --> 00:10:04,194 I just felt like a normal 182 00:10:04,336 --> 00:10:08,067 a normal little girl, and, you know, 183 00:10:08,206 --> 00:10:10,231 I had girlfriends, and I had all my dolls and, 184 00:10:10,375 --> 00:10:14,709 you know, everything was just just normal. 185 00:10:15,680 --> 00:10:18,444 It wasn't until she went to college to study anatomy 186 00:10:18,583 --> 00:10:20,346 that she realised something was wrong. 187 00:10:21,119 --> 00:10:24,384 Quite simply, at the age of 19 188 00:10:24,522 --> 00:10:26,490 she still hadn't gone through puberty. 189 00:10:26,625 --> 00:10:29,219 I felt self-conscious because I wasn't developing like 190 00:10:29,361 --> 00:10:30,953 all my girlfriends were developing. 191 00:10:31,096 --> 00:10:33,189 You know, it's painful to stand out and be different. 192 00:10:33,331 --> 00:10:36,425 And I wanted to find out why I wasn't starting my period. 193 00:10:36,568 --> 00:10:38,365 So I ended up going to the gynaecologist 194 00:10:38,503 --> 00:10:39,401 for the first time. 195 00:10:39,704 --> 00:10:41,262 I came into class one day very upset, 196 00:10:41,406 --> 00:10:44,603 and - because I had gone to the doctor a few days before, 197 00:10:44,743 --> 00:10:48,975 and they had very simply just written XY on a piece of paper, 198 00:10:49,114 --> 00:10:50,547 and gave that to me. 199 00:10:50,682 --> 00:10:51,808 And that was supposed to be 200 00:10:51,950 --> 00:10:55,010 the explanation of why I was the way I was. 201 00:10:56,321 --> 00:10:58,255 So why did Jan become a woman 202 00:10:58,390 --> 00:11:00,483 when her genes were those of a man? 203 00:11:01,660 --> 00:11:04,925 The answer lies in understanding how the male sex chromosome 204 00:11:05,063 --> 00:11:06,963 the Y chromosome -works. 205 00:11:10,035 --> 00:11:13,596 The most obvious thing about the Y is that it isn't very big. 206 00:11:14,739 --> 00:11:19,870 The Y has around 60 genes and the eggs around 3,000. 207 00:11:20,378 --> 00:11:23,836 The Y chromosome is the smallest chromosome, 208 00:11:23,982 --> 00:11:25,847 and when you look at it in detail 209 00:11:25,984 --> 00:11:29,784 only a very small part of it actually codes for anything. 210 00:11:29,921 --> 00:11:32,116 So most of its a desert. 211 00:11:33,058 --> 00:11:37,119 Peter Good fellow knows the Y chromosome intimately. 212 00:11:37,495 --> 00:11:41,431 He found the gene responsible for turning embryos into men. 213 00:11:43,368 --> 00:11:47,498 It's on the Y chromosome, and it's called the SRY. 214 00:11:48,506 --> 00:11:51,566 It's hugely influential in how men develop. 215 00:11:52,644 --> 00:11:54,134 And this is it. 216 00:11:55,413 --> 00:11:58,246 But being very important doesn't mean it's big. 217 00:11:59,551 --> 00:12:02,952 Imagine that your DNA was a piece of string, 218 00:12:03,288 --> 00:12:04,255 so you could see it. 219 00:12:04,389 --> 00:12:06,914 So we've magnified the DNA 220 00:12:07,058 --> 00:12:11,222 which is present in every cell in your body so it's visible. 221 00:12:14,399 --> 00:12:19,393 And that piece of string now would stretch from here to Moscow. 222 00:12:20,505 --> 00:12:24,168 Now, if we were to start a journey from here to Moscow, 223 00:12:24,309 --> 00:12:27,676 on foot, the Y chromosome would represent 224 00:12:27,812 --> 00:12:30,144 the first 20 miles of that journey. 225 00:12:31,116 --> 00:12:37,487 And the SRY gene would be the first step on the journey to Moscow. 226 00:12:38,456 --> 00:12:41,482 It takes 30,000 genes to build a human, 227 00:12:42,594 --> 00:12:46,189 but just one gene -the SRY to build a man. 228 00:12:47,732 --> 00:12:49,723 The SRY is a switch which clicks 229 00:12:49,868 --> 00:12:52,336 when the foetus is around six weeks old. 230 00:12:52,871 --> 00:12:55,965 Until then, the baby could become either male or female. 231 00:12:56,941 --> 00:12:58,932 When the SRY is switched on, 232 00:12:59,077 --> 00:13:02,478 it fires up the development of the male sex organs. 233 00:13:02,714 --> 00:13:04,739 There's a tiny genetic difference, 234 00:13:04,883 --> 00:13:08,751 that genetic difference leads to one key difference, 235 00:13:08,887 --> 00:13:14,792 and that one key difference is men have testes and women have ovaries. 236 00:13:14,926 --> 00:13:17,724 And it's what's produced by the testes 237 00:13:17,862 --> 00:13:19,557 and what's produced by the ovaries 238 00:13:19,697 --> 00:13:22,666 which is responsible for the differences 239 00:13:22,801 --> 00:13:25,031 you see between males and females. 240 00:13:26,604 --> 00:13:29,698 But Jan Johnson has a copy of the SRY gene, 241 00:13:29,841 --> 00:13:31,536 so why isn't she a man? 242 00:13:32,477 --> 00:13:36,470 Well, the SRY triggers development of the testes, 243 00:13:37,582 --> 00:13:41,678 and they produce a very versatile hormone called testosterone. 244 00:13:41,986 --> 00:13:43,476 Testosterone is a steroid hormone, 245 00:13:43,621 --> 00:13:46,715 and one of the things that steroid hormones are excellent 246 00:13:46,858 --> 00:13:49,122 at is going in lots of different places in the body 247 00:13:49,260 --> 00:13:51,592 and instigating lots of different changes, 248 00:13:51,729 --> 00:13:54,323 and testosterone's a beautiful example of that. 249 00:13:55,867 --> 00:14:00,600 Testosterone rampages through the male embryo building muscle 250 00:14:00,872 --> 00:14:03,238 and developing the cardio vascular system. 251 00:14:04,542 --> 00:14:08,501 It's this hormone which makes men so very different from women. 252 00:14:09,314 --> 00:14:11,680 To a remarkable extent, testosterone is responsible 253 00:14:11,816 --> 00:14:13,579 for the masculinisation of the human body. 254 00:14:13,718 --> 00:14:14,707 It's really, in some ways, 255 00:14:14,853 --> 00:14:16,821 it's kind of surprising that this one agent 256 00:14:16,955 --> 00:14:18,752 seems to start this cascade 257 00:14:18,890 --> 00:14:20,448 that has so many different effects. 258 00:14:25,396 --> 00:14:27,887 And it's testosterone that is the answer 259 00:14:28,032 --> 00:14:31,661 to the riddle of Jan Johnson's unusual genetic make up. 260 00:14:34,939 --> 00:14:40,070 Jan has a condition called AIS Androgen Insensitivity Syndrome. 261 00:14:40,845 --> 00:14:42,779 Her genes make testosterone, 262 00:14:43,314 --> 00:14:45,612 but her body can't respond to it. 263 00:14:46,417 --> 00:14:48,317 If it can't react to testosterone 264 00:14:48,453 --> 00:14:52,082 the foetus assumes the default position, which is female. 265 00:14:53,191 --> 00:14:55,989 And that's exactly what happened to Jan Johnson. 266 00:14:57,228 --> 00:14:59,196 The discovery that she's genetically male 267 00:14:59,330 --> 00:15:00,854 was so traumatising 268 00:15:00,999 --> 00:15:03,194 that she couldn't even tell her then boyfriend 269 00:15:03,334 --> 00:15:04,995 and future husband, Peter. 270 00:15:06,204 --> 00:15:08,263 I told him well, I'm unable to have children, 271 00:15:08,406 --> 00:15:10,636 and, you know, here's my situation, 272 00:15:10,775 --> 00:15:12,242 and I don't have my period. 273 00:15:12,377 --> 00:15:16,973 But I never really got into the nuts and bolts of it with him. 274 00:15:17,115 --> 00:15:17,410 Why? 275 00:15:17,548 --> 00:15:21,712 Because it was embarrassing for me. 276 00:15:21,853 --> 00:15:24,413 I didn't want to talk about it. 277 00:15:25,256 --> 00:15:27,554 And I didn't think anyone wanted to hear about it. 278 00:15:30,228 --> 00:15:31,855 The only person she felt would listen 279 00:15:31,996 --> 00:15:37,059 and understand was her anatomy professor Kris Blodget. 280 00:15:37,201 --> 00:15:38,099 And I said well, 281 00:15:38,236 --> 00:15:42,605 the first thing I want you to know is you're a normal girl, 282 00:15:42,740 --> 00:15:44,867 you're not a boy, you're definitely a girl, 283 00:15:45,009 --> 00:15:46,636 you're a very feminine girl. 284 00:15:46,778 --> 00:15:48,643 This should not change your life. 285 00:15:48,780 --> 00:15:53,149 It was devastating to know that I had XY chromosomes, 286 00:15:53,284 --> 00:15:55,548 and those are the same chromosomes a man would have. 287 00:15:55,687 --> 00:15:59,885 Then I said, well, you can't respond to testosterone so, 288 00:16:00,024 --> 00:16:02,618 actually, you're more feminine than an actual 289 00:16:02,760 --> 00:16:08,062 than an XX female who can respond to testosterone, too. 290 00:16:08,199 --> 00:16:15,367 So I said - I said the people that have this develop as normal female, 291 00:16:15,506 --> 00:16:18,839 usually above-average in attractiveness, 292 00:16:18,977 --> 00:16:21,309 they're tall, they're very feminine. 293 00:16:23,247 --> 00:16:26,512 Professor Blodget then got Jan to check her own genes. 294 00:16:27,618 --> 00:16:30,086 So she could see there was nothing to be frightened of. 295 00:16:31,756 --> 00:16:35,522 She was probably the strongest female person 296 00:16:35,660 --> 00:16:37,287 in my life back then. 297 00:16:37,662 --> 00:16:40,995 My mum couldn't really offer any support, 298 00:16:41,132 --> 00:16:44,898 and you know, my siblings certainly couldn't offer support. 299 00:16:45,036 --> 00:16:46,765 So I really didn't have anyone 300 00:16:47,872 --> 00:16:50,932 who could explain it to me the way she explained it to me. 301 00:16:51,943 --> 00:16:54,002 And the pain and the hurt of the discovery 302 00:16:54,145 --> 00:16:57,376 that she was genetically male came flooding back 303 00:16:57,949 --> 00:17:02,613 when they met for the first time since Jan left college 25 years ago. 304 00:17:21,339 --> 00:17:23,534 I was hoping that she's put it behind her, 305 00:17:23,674 --> 00:17:26,472 and was leading a normal life and not considering it a deep, 306 00:17:26,611 --> 00:17:30,809 dark secret, and realised that she was totally feminine and normal. 307 00:17:31,449 --> 00:17:33,713 She really made me feel a lot better about myself. 308 00:17:33,851 --> 00:17:36,319 So it was great to see her again. 309 00:17:40,525 --> 00:17:44,723 Jan's unusual genetic make up means she can't have children, 310 00:17:44,862 --> 00:17:46,386 the thing she wants most. 311 00:17:47,598 --> 00:17:50,066 She doesn't have a womb or ovaries. 312 00:17:50,668 --> 00:17:53,933 And that's put an inevitable strain on her marriage. 313 00:17:56,107 --> 00:17:58,007 We've been together for 23 years. 314 00:17:58,142 --> 00:17:59,507 We've been married for 13 years. 315 00:17:59,644 --> 00:18:02,579 And we've certainly had our ups and downs, 316 00:18:02,713 --> 00:18:08,618 and some of the - some of the deepest lows were over, 317 00:18:08,753 --> 00:18:10,118 you know, adoption. 318 00:18:10,254 --> 00:18:12,882 And you know, and that's unfortunate. 319 00:18:13,024 --> 00:18:16,357 I would - I hoped back then that I would meet someone 320 00:18:16,494 --> 00:18:18,462 that would want to adopt children, 321 00:18:18,596 --> 00:18:22,123 and it just - it just didn't work out. 322 00:18:22,266 --> 00:18:23,756 It was not the right time, 323 00:18:23,901 --> 00:18:27,701 and we didn't have the money or, you know, 324 00:18:27,839 --> 00:18:31,240 for some reason or another it just never it never worked out. 325 00:18:34,212 --> 00:18:35,702 Ironically, Jan Johnson works 326 00:18:35,847 --> 00:18:38,748 for a company which makes high-tech medical equipment. 327 00:18:41,252 --> 00:18:45,450 But there's no technological solution to her inability to conceive, 328 00:18:49,494 --> 00:18:52,156 She just doesn't have the right genes. 329 00:18:52,897 --> 00:18:56,196 Instead of a Y, she'd need another X. 330 00:18:56,801 --> 00:19:01,170 That's because the second X sends out instructions to make ovaries. 331 00:19:01,706 --> 00:19:04,869 These produce the female hormone oestrogen 332 00:19:05,576 --> 00:19:09,774 which builds a womb and fallopian tubes. 333 00:19:11,582 --> 00:19:13,015 The discovery that men are created 334 00:19:13,151 --> 00:19:16,643 from a female blueprint was certainly a big surprise 335 00:19:16,787 --> 00:19:18,550 and contradicts previously held notions 336 00:19:18,689 --> 00:19:21,817 about the relative importance of men and women. 337 00:19:24,061 --> 00:19:27,155 Societies have decided the relative importance of men 338 00:19:27,298 --> 00:19:29,357 and women for thousands of years. 339 00:19:29,500 --> 00:19:33,368 By and large, the men are regarded as more important than the women. 340 00:19:33,804 --> 00:19:35,738 So when biology started to catch up, 341 00:19:35,873 --> 00:19:37,966 at first it looked to reinforce that; 342 00:19:38,109 --> 00:19:40,600 the idea was that the sperm contained the little person 343 00:19:40,745 --> 00:19:46,081 and the woman was just the sort of soil in which the man would grow, 344 00:19:46,217 --> 00:19:47,047 the baby would grow. 345 00:19:47,185 --> 00:19:48,777 Gradually, as we've learnt more about it, 346 00:19:48,920 --> 00:19:51,514 we've realised that the mum is rather more important, 347 00:19:51,656 --> 00:19:52,850 and the woman's rather more important. 348 00:19:52,990 --> 00:19:56,016 And the big shock came when it was realised 349 00:19:56,160 --> 00:19:59,323 that if you don't have a sex chromosome, 350 00:19:59,463 --> 00:20:02,830 or one of the sex chromosomes you don't come out as a boy, 351 00:20:02,967 --> 00:20:03,956 you come out as a girl. 352 00:20:04,101 --> 00:20:06,626 So what that tells us is that the Bible 353 00:20:06,771 --> 00:20:09,262 was fundamentally the wrong way round. 354 00:20:09,707 --> 00:20:11,937 Woman was not born of man's rib, 355 00:20:12,076 --> 00:20:13,065 it's the other way round. 356 00:20:13,211 --> 00:20:15,202 Adam, if anything, came from Eve's rib. 357 00:20:15,513 --> 00:20:19,279 So the male is an adapted form of the female. 358 00:20:20,685 --> 00:20:23,483 One very obvious remnant of our female past 359 00:20:23,621 --> 00:20:26,522 can be found on every male chest. 360 00:20:28,292 --> 00:20:29,452 Nipples. 361 00:20:30,795 --> 00:20:32,285 The reason men have nipples is 362 00:20:32,430 --> 00:20:34,091 because they developed in the foetus 363 00:20:34,232 --> 00:20:36,530 before testosterone kicked in. 364 00:20:38,202 --> 00:20:39,533 But if a hit of testosterone is 365 00:20:39,670 --> 00:20:42,764 all it takes to turn the female form into the male... 366 00:20:47,612 --> 00:20:51,946 what would happen if a genetic female were to be exposed to it? 367 00:20:52,450 --> 00:20:54,611 Max Toth, a software programmer, 368 00:20:54,752 --> 00:20:57,050 is physically and genetically a woman. 369 00:20:57,688 --> 00:21:01,351 She wants to see if testosterone can turn her into a man. 370 00:21:03,094 --> 00:21:05,221 I remembered having this distinct moment 371 00:21:05,363 --> 00:21:07,490 where I thought that God had made a mistake 372 00:21:07,632 --> 00:21:08,690 and that I should have been a boy, 373 00:21:08,833 --> 00:21:09,492 which I thought was interesting, 374 00:21:09,634 --> 00:21:11,864 because I grew up in an atheist household. 375 00:21:12,303 --> 00:21:15,329 I didn't really have a good conception of what God was, 376 00:21:15,473 --> 00:21:17,771 or that there was an entity that could have made a mistake. 377 00:21:17,908 --> 00:21:21,173 But I remembered having this very clear moment. 378 00:21:25,950 --> 00:21:28,851 Science can't explain why she feels like this, 379 00:21:28,986 --> 00:21:31,284 but she knows she's not right the way she is. 380 00:21:31,889 --> 00:21:34,380 She wants the body and looks of a man. 381 00:21:35,226 --> 00:21:37,160 The idea that I could do this, 382 00:21:37,295 --> 00:21:40,093 that I could change something about the way that I was made up, 383 00:21:40,231 --> 00:21:42,131 that I can change the way that my body 384 00:21:42,266 --> 00:21:45,235 had been born was very exciting to me. 385 00:21:48,472 --> 00:21:50,565 To masculinise her body, 386 00:21:50,875 --> 00:21:54,140 Max is planning to take a course of testosterone. 387 00:21:54,912 --> 00:21:56,903 I'm taking my life into my own hands in a lot of ways 388 00:21:57,048 --> 00:21:58,481 because there aren't a lot of studies 389 00:21:58,616 --> 00:22:00,914 about the long-term effects of testosterone. 390 00:22:03,321 --> 00:22:07,553 But Max really wanted to do it and have it properly evaluated. 391 00:22:08,659 --> 00:22:12,220 So we followed her testosterone treatment for six months to see 392 00:22:12,363 --> 00:22:17,232 what effect it would have, not only on her body, but also on her mind. 393 00:22:22,173 --> 00:22:24,539 The body changes will be the most obvious. 394 00:22:24,842 --> 00:22:26,707 Testosterone should build her muscles 395 00:22:26,844 --> 00:22:28,311 and make her more powerful, 396 00:22:28,979 --> 00:22:31,243 which should mean that she'll run faster. 397 00:22:35,419 --> 00:22:39,412 To test this effect, we set up a round course of just over a mile 398 00:22:39,557 --> 00:22:42,526 in Pan Handle Park in the middle of San Francisco, 399 00:22:42,860 --> 00:22:44,259 and recorded her time. 400 00:22:46,831 --> 00:22:48,355 11 minutes, exactly. 401 00:22:51,502 --> 00:22:53,299 We'll come back and check that time 402 00:22:53,437 --> 00:22:56,565 as we monitor the progress of her testosterone treatment. 403 00:22:58,642 --> 00:23:01,008 Apart from the rather obvious physical effects, 404 00:23:01,145 --> 00:23:04,376 testosterone might also change the way her brain works. 405 00:23:04,782 --> 00:23:07,808 So we had her brain scanned by Doctor Ruben Gur, 406 00:23:07,952 --> 00:23:09,715 one of the world's leading scientists 407 00:23:09,854 --> 00:23:12,084 on the effects of hormones on the brain. 408 00:23:19,029 --> 00:23:21,964 Doctor Gur also put Max through a battery of practical 409 00:23:22,099 --> 00:23:24,124 and psychological tests designed to see 410 00:23:24,268 --> 00:23:27,032 just how feminine Max currently is. 411 00:23:33,043 --> 00:23:39,107 Max shows a fairly typical female profile cognitively, 412 00:23:39,250 --> 00:23:46,053 and I'd be curious to see whether there is a change in that. 413 00:23:48,392 --> 00:23:51,327 At the moment, by any measure, Max is a woman. 414 00:23:54,231 --> 00:23:56,199 But that's about to change. 415 00:23:58,335 --> 00:23:59,734 I had a birthday party recently, 416 00:23:59,870 --> 00:24:01,701 and I thought as part of the festivities 417 00:24:01,839 --> 00:24:04,831 that I would allow people to express themselves artistically 418 00:24:04,975 --> 00:24:07,170 by drawing my future facial hair. 419 00:24:07,311 --> 00:24:09,905 So I gave people this form, 420 00:24:11,248 --> 00:24:13,648 and this is some of the stuff they came up with. 421 00:24:13,784 --> 00:24:14,751 Trucker Max. 422 00:24:15,886 --> 00:24:17,217 Flaming Max. 423 00:24:18,189 --> 00:24:19,554 Spit curls. 424 00:24:20,558 --> 00:24:22,856 Bad Eighties rock star. 425 00:24:23,327 --> 00:24:25,090 Funky shimmer boy. 426 00:24:25,463 --> 00:24:27,192 My absolute favourite, 427 00:24:27,765 --> 00:24:31,132 the I'm secure in my masculinity Max. 428 00:24:33,437 --> 00:24:37,533 Today's the day when Max receives her first shot of testosterone. 429 00:24:44,348 --> 00:24:48,341 From now on, she wants to be referred to as 'he'. 430 00:24:48,486 --> 00:24:49,612 So this is the big day, huh? 431 00:24:49,753 --> 00:24:50,310 Yep. 432 00:24:50,988 --> 00:24:52,114 It's only a really small dose. 433 00:24:52,590 --> 00:24:53,682 So it's a very small volume. 434 00:24:53,824 --> 00:24:54,381 Right. 435 00:24:54,525 --> 00:24:55,514 So it's not a problem. 436 00:24:55,659 --> 00:24:57,354 I actually still have to go draw it up. 437 00:24:57,495 --> 00:24:57,756 Okay. 438 00:24:57,895 --> 00:25:00,261 I just wanted to check what dose that we're starting you on. 439 00:25:00,397 --> 00:25:00,920 Ckay. 440 00:25:01,732 --> 00:25:05,099 Max will soon be exposed to the same level of testosterone 441 00:25:05,236 --> 00:25:07,329 as a young boy going through puberty. 442 00:25:08,038 --> 00:25:09,801 Okey-doke. Here we go. 443 00:25:09,940 --> 00:25:10,804 Okay. 444 00:25:10,941 --> 00:25:12,135 There you go. 445 00:25:12,276 --> 00:25:14,608 On three - one, two, three... 446 00:25:17,848 --> 00:25:19,042 There you go, that's it. 447 00:25:19,183 --> 00:25:22,209 A little blood and everything. Okay. 448 00:25:22,353 --> 00:25:23,115 I'll just put a BandAid on there. 449 00:25:23,254 --> 00:25:25,222 Okay. Cool. 450 00:25:25,356 --> 00:25:25,651 Okay? 451 00:25:25,789 --> 00:25:26,153 Thank you. 452 00:25:26,290 --> 00:25:27,621 You're all set. You're very welcome. 453 00:25:27,758 --> 00:25:29,658 It was kind of exciting and it was kind of scary. 454 00:25:29,793 --> 00:25:31,090 And my arm hurt. 455 00:25:32,329 --> 00:25:37,096 I'm rolling the dice and seeing what it is that's gonna happen, 456 00:25:37,234 --> 00:25:38,599 and I have my own personal beliefs 457 00:25:38,736 --> 00:25:45,369 about kind of how much one's personality shifts aren't bio-chemical. 458 00:25:45,509 --> 00:25:48,774 I'm kind of in the camp of I think that a lot of stuff is sociological. 459 00:25:48,913 --> 00:25:51,973 And so - but - and I'm willing to stake my life on it, 460 00:25:52,116 --> 00:25:54,050 and the better part of my bio-chemistry. 461 00:25:54,184 --> 00:25:57,551 So we're gonna see at the end of this, you know, 462 00:25:57,688 --> 00:26:00,054 I don't want to wake up and be knuckle-dragging 463 00:26:00,190 --> 00:26:02,317 and chest-thumping and things like that. 464 00:26:02,459 --> 00:26:03,289 So it does make me nervous. 465 00:26:03,427 --> 00:26:04,758 But I don't think I will. 466 00:26:06,230 --> 00:26:09,927 Women naturally have some testosterone in their bodies, 467 00:26:10,067 --> 00:26:12,535 but men have ten times as much. 468 00:26:12,836 --> 00:26:14,861 And some men have more than others. 469 00:26:15,873 --> 00:26:18,068 But does it really matter what your level is? 470 00:26:21,211 --> 00:26:23,042 Take a look at these athletes; 471 00:26:23,681 --> 00:26:27,640 they're all highly trained 100 metre specialists, and about the same age. 472 00:26:28,752 --> 00:26:33,155 But if they raced, could you tell just by looking at them, who'd win? 473 00:26:38,195 --> 00:26:39,856 Well, this man, Doctor John Manning, 474 00:26:39,997 --> 00:26:43,364 says he can, just by measuring their fingers, 475 00:26:44,034 --> 00:26:45,763 and that's because testosterone levels 476 00:26:45,903 --> 00:26:48,701 and finger lengths are intimately linked. 477 00:26:49,373 --> 00:26:50,704 We've known for a long time 478 00:26:50,841 --> 00:26:53,332 that there's a sex difference in the fingers. 479 00:26:53,477 --> 00:26:56,002 It's quite a subtle difference and, in general, 480 00:26:56,146 --> 00:26:59,946 people don't talk about it and don't know about it even. 481 00:27:00,851 --> 00:27:02,682 It starts in the womb. 482 00:27:03,554 --> 00:27:06,079 Hormones rush through the developing embryo, 483 00:27:06,223 --> 00:27:09,590 building and shaping the body, including the fingers. 484 00:27:10,294 --> 00:27:12,819 And the effects can be seen years later. 485 00:27:13,530 --> 00:27:15,964 Compare the hand of the man on the left 486 00:27:16,100 --> 00:27:18,125 with that of the woman on the right. 487 00:27:19,136 --> 00:27:22,697 The man's ring finger is longer than his index finger. 488 00:27:23,607 --> 00:27:24,801 In the case of the woman, 489 00:27:24,942 --> 00:27:29,845 it's the opposite; the index finger is longer than the ring finger. 490 00:27:31,015 --> 00:27:34,041 We think that the length of the ring-finger is 491 00:27:34,184 --> 00:27:36,118 a direct indicator of the amount of 492 00:27:36,253 --> 00:27:39,552 testosterone one's exposed to in utero, 493 00:27:39,690 --> 00:27:43,126 and the length of the index finger indicated the amount of oestrogen 494 00:27:43,260 --> 00:27:45,125 you've been exposed to in utero. 495 00:27:45,262 --> 00:27:49,198 So it's the relative lengths of these two fingers that are important. 496 00:27:49,333 --> 00:27:51,995 If you've got a longer ring finger than your index finger 497 00:27:52,136 --> 00:27:55,071 you have been exposed to high testosterone. 498 00:27:55,205 --> 00:27:58,641 If you've got a longer index finger than ring finger 499 00:27:58,776 --> 00:28:01,870 you've been exposed to low testosterone and high oestrogen. 500 00:28:02,913 --> 00:28:07,043 Doctor Manning is one of the world's leading experts on testosterone. 501 00:28:08,385 --> 00:28:10,376 In the course of his investigations 502 00:28:10,521 --> 00:28:12,318 he's worked both with infertile men 503 00:28:12,456 --> 00:28:14,924 and with professional footballers. 504 00:28:15,693 --> 00:28:18,685 He believes pre-natal testosterone plays a big part 505 00:28:18,829 --> 00:28:21,354 in determining future athletic performance. 506 00:28:26,003 --> 00:28:28,870 But he's never put his considerable reputation on the line 507 00:28:29,006 --> 00:28:31,031 by trying to predict the result of a race 508 00:28:31,175 --> 00:28:34,906 between athletes he's never met or seen run. 509 00:28:38,315 --> 00:28:39,907 This is a high risk business, I think. 510 00:28:40,050 --> 00:28:42,848 You know, it would be nice to have ten races 511 00:28:42,986 --> 00:28:44,851 with ten different groups of athletes, 512 00:28:44,988 --> 00:28:49,425 and I think we would probably be able to predict sort of eight 513 00:28:49,560 --> 00:28:52,825 out of the ten winners of those ten races. 514 00:28:52,963 --> 00:28:57,366 One race is highly chancy, but I'll give it a go. 515 00:28:58,035 --> 00:29:00,526 So, why should it work? Well, 516 00:29:00,671 --> 00:29:03,572 testosterone helps develop the heart and lungs, 517 00:29:03,707 --> 00:29:05,607 the engine of any athlete. 518 00:29:06,577 --> 00:29:08,704 Crudely speaking, the bigger the hit of testosterone 519 00:29:08,846 --> 00:29:12,441 in the womb the greater the physical potential of the foetus. 520 00:29:13,851 --> 00:29:16,081 It's obviously impossible to say with any certainty 521 00:29:16,220 --> 00:29:18,620 how much testosterone these men were exposed to 522 00:29:18,756 --> 00:29:20,314 when in their mother's wombs. 523 00:29:20,791 --> 00:29:23,419 Instead, Doctor Manning is using their fingers 524 00:29:23,560 --> 00:29:26,495 as a guide to the size of their in utero hit. 525 00:29:28,298 --> 00:29:31,392 The runners and their coach aren't entirely convinced. 526 00:29:32,169 --> 00:29:33,227 I don't think it's gonna work. 527 00:29:33,370 --> 00:29:35,270 I'm not confident at all about it. 528 00:29:35,405 --> 00:29:37,202 We're all probably a bit sceptical about it. 529 00:29:37,341 --> 00:29:40,833 But I mean it's got undue possibilities if there's something in it. 530 00:29:40,978 --> 00:29:43,879 I cannot see it, why your hand measurements 531 00:29:44,014 --> 00:29:45,345 would predict how fast you run. 532 00:29:45,482 --> 00:29:47,882 I can't see any connection between the two. 533 00:29:52,556 --> 00:29:54,251 While the lads get ready to run, 534 00:29:54,591 --> 00:29:57,856 Doctor Manning finds a quiet corner to make his calculations. 535 00:30:02,232 --> 00:30:03,790 So has he found a winner? 536 00:30:05,102 --> 00:30:06,865 These are five very, very fine young men. 537 00:30:07,004 --> 00:30:08,801 I mean they're excellent athletes, 538 00:30:08,939 --> 00:30:12,773 and they've all had quite high testosterone levels before birth, 539 00:30:12,910 --> 00:30:14,275 as one would expect. 540 00:30:14,411 --> 00:30:17,869 But there are clear differences between them. 541 00:30:19,249 --> 00:30:22,776 As far as he's concerned, these are the winning fingers. 542 00:30:23,253 --> 00:30:24,845 They belong to Tim Abeyu. 543 00:30:25,923 --> 00:30:28,016 And you can see the difference between his ring finger 544 00:30:28,158 --> 00:30:30,592 and his index finger is quite marked. 545 00:30:32,429 --> 00:30:34,897 Compare his hand to one of the other runners. 546 00:30:35,899 --> 00:30:37,332 This is Ian Deith's hand. 547 00:30:37,467 --> 00:30:39,492 And the difference is obvious. 548 00:30:40,771 --> 00:30:42,671 Tim's got a very low ratio, 549 00:30:42,806 --> 00:30:45,070 and I think has tremendous potential. 550 00:30:45,209 --> 00:30:46,836 I think he's a very, very fast running. 551 00:30:46,977 --> 00:30:48,376 So I'd go for Tim. 552 00:30:50,047 --> 00:30:51,605 As they prepare to race, 553 00:30:51,748 --> 00:30:54,717 none of the athletes know Doctor Manning's selection. 554 00:30:55,619 --> 00:30:58,019 So, the moment of truth. 555 00:30:58,822 --> 00:31:01,814 They line up from the left, in lane 1, it's Lawrence Obi. 556 00:31:01,959 --> 00:31:03,358 In lane 2, it's Jonathan Regis. 557 00:31:03,493 --> 00:31:06,621 3 is Ian Deith. 4, James Ellington. 558 00:31:06,763 --> 00:31:10,494 And in 5, Doctor Manning's selection Tim Abeyu. 559 00:31:18,809 --> 00:31:20,868 And Abeyu's got an absolute flier. 560 00:31:21,011 --> 00:31:22,535 He storms out of the blocks. 561 00:31:23,647 --> 00:31:25,205 Doctor Manning looks like he's picked a winner here. 562 00:31:25,349 --> 00:31:26,543 But Obi in lane 1 is fighting back. 563 00:31:26,683 --> 00:31:28,674 But the big man in lane 5 is pouring it on. 564 00:31:28,819 --> 00:31:31,219 And Abeyu's got too much... and Abeyu wins. 565 00:31:34,591 --> 00:31:36,456 So the prediction was spot on, 566 00:31:36,894 --> 00:31:39,089 which was a huge relief for Doctor Manning. 567 00:31:39,696 --> 00:31:43,462 Well, I was very, very pleased to see Tim go across that line first. 568 00:31:43,600 --> 00:31:46,398 And in great style as well. 569 00:31:46,837 --> 00:31:47,861 Be interested to know 570 00:31:48,005 --> 00:31:50,496 if they have a race for elite athletes 571 00:31:50,641 --> 00:31:52,939 at the very top of their game, 572 00:31:53,310 --> 00:31:54,504 if the same principle applies. 573 00:31:55,612 --> 00:31:57,807 Doctor Manning is conducting similar research 574 00:31:57,948 --> 00:31:59,643 with the British Ski Federation, 575 00:31:59,783 --> 00:32:02,513 helping to select potential downhill champions. 576 00:32:02,819 --> 00:32:05,049 Men are engineered in such a way 577 00:32:05,188 --> 00:32:08,055 as to be able to compete physically against other men. 578 00:32:08,191 --> 00:32:12,150 So the more testosterone a foetus has, a male foetus has, 579 00:32:12,296 --> 00:32:15,060 the more efficient his cardio vascular system 580 00:32:15,198 --> 00:32:16,631 is going to be after birth. 581 00:32:16,767 --> 00:32:21,670 If you don't get exposure early and to high amounts of testosterone, 582 00:32:21,805 --> 00:32:25,241 then it will affect your competitive 583 00:32:25,375 --> 00:32:27,866 physical competitive abilities later in life. 584 00:32:32,115 --> 00:32:34,913 In the light of such findings, parents might be tempted to 585 00:32:35,052 --> 00:32:37,987 add a touch of testosterone to their growing foetuses 586 00:32:38,121 --> 00:32:40,385 in the hope this will make them more athletic. 587 00:32:41,792 --> 00:32:43,157 But building super athletes 588 00:32:43,293 --> 00:32:46,524 by manipulating testosterone would be dangerous. 589 00:32:46,930 --> 00:32:51,060 And anyway, there's much more sophisticated technology available. 590 00:32:52,669 --> 00:32:54,864 You can definitely create super athletes in the future, 591 00:32:55,005 --> 00:32:57,405 and there's a much easier way to do that than to muck 592 00:32:57,541 --> 00:33:00,704 muck around with the with the embryo itself. 593 00:33:00,844 --> 00:33:03,039 The better way to do this is to create 594 00:33:03,180 --> 00:33:05,614 the cassette of genes that you want in the laboratory. 595 00:33:05,749 --> 00:33:08,843 So even before you come near an embryo in your laboratory, 596 00:33:08,986 --> 00:33:10,647 you put together each of the genes 597 00:33:10,787 --> 00:33:13,187 that you want to put into your future child, 598 00:33:13,323 --> 00:33:13,846 you put them together, 599 00:33:13,991 --> 00:33:15,652 you make sure that they're working properly 600 00:33:15,792 --> 00:33:18,260 and you put them onto a brand new chromosome, 601 00:33:18,395 --> 00:33:19,794 and then you take this chromosome 602 00:33:19,930 --> 00:33:23,024 which has already vetted for perfection, 603 00:33:23,166 --> 00:33:25,634 you take this chromosome and put it into the embryo. 604 00:33:25,769 --> 00:33:29,603 And that's a much more efficient way of changing a large number 605 00:33:29,740 --> 00:33:31,867 of genic characteristics at the same time. 606 00:33:33,377 --> 00:33:36,676 If you think that sounds like science fiction you'd be wrong. 607 00:33:39,082 --> 00:33:40,777 Artificial chromosomes are not just figments 608 00:33:40,917 --> 00:33:42,817 in the imagination of scientists, 609 00:33:42,953 --> 00:33:44,545 they've already been created in the laboratory, 610 00:33:44,688 --> 00:33:47,521 they've already been placed into mouse embryos 611 00:33:47,657 --> 00:33:51,218 and we already have mice born with these extra chromosomes. 612 00:33:51,361 --> 00:33:54,387 And if you can do it in mice you can do it in humans. 613 00:34:00,704 --> 00:34:04,640 But doing it in humans would be a big and disturbing advance. 614 00:34:06,376 --> 00:34:08,640 The differences, on a genetic level, 615 00:34:08,779 --> 00:34:10,770 between us and our early ancestors like 616 00:34:10,914 --> 00:34:14,441 Australopithecus are tiny, less than 1%. 617 00:34:18,422 --> 00:34:21,858 If it only took a few tiny changes in our DNA 618 00:34:21,992 --> 00:34:24,426 to go from Australopithecus to us, 619 00:34:25,028 --> 00:34:30,022 imagine where implanting an array of artificial chromosomes might lead to. 620 00:34:38,775 --> 00:34:40,868 But perhaps it will never happen. 621 00:34:42,412 --> 00:34:45,313 We've got to be aware that it's not easy to do. 622 00:34:45,449 --> 00:34:47,747 Even if you achieve it, 623 00:34:47,884 --> 00:34:50,216 you've then got to say can I keep doing it? 624 00:34:50,353 --> 00:34:53,151 We've been to the moon once, but there's no hotels there. 625 00:34:53,290 --> 00:34:55,554 So the ability to do it once is not the same 626 00:34:55,692 --> 00:34:58,058 as being able to do it on a wet Wednesday in Doncaster. 627 00:34:58,195 --> 00:35:00,026 And I have great concerns about just 628 00:35:00,163 --> 00:35:04,327 the complexity of these techniques and their applicability, 629 00:35:04,468 --> 00:35:06,663 even for severe diseases. 630 00:35:06,803 --> 00:35:08,998 But even if you got it to the stage 631 00:35:09,139 --> 00:35:10,333 where you could make it work 632 00:35:10,474 --> 00:35:12,271 and you could cure some rare diseases 633 00:35:12,409 --> 00:35:17,711 or some serious diseases would you actually use that very precious, 634 00:35:17,848 --> 00:35:21,249 very expensive and challenging technology to do something 635 00:35:21,384 --> 00:35:24,945 as trivial as social modification of 636 00:35:25,088 --> 00:35:28,114 a person to make them bigger, smarter or whatever. 637 00:35:28,258 --> 00:35:30,488 You know, which island full of mad scientists 638 00:35:30,627 --> 00:35:32,117 is actually doing to do that? 639 00:35:32,262 --> 00:35:33,593 I don't think they exist. 640 00:35:33,730 --> 00:35:37,222 I don't think they would allow their precious reserves 641 00:35:37,367 --> 00:35:39,858 and resources to be used for that purpose. 642 00:35:43,540 --> 00:35:47,306 But expensive and challenging technology is being used all the time 643 00:35:47,444 --> 00:35:49,912 for purposes its makers did not intend. 644 00:35:51,281 --> 00:35:54,808 Testosterone wasn't synthesised to turn women into men. 645 00:35:55,886 --> 00:35:57,751 Yet, it's being used for that. 646 00:36:03,827 --> 00:36:07,524 It's six months since Max first started taking testosterone. 647 00:36:08,265 --> 00:36:09,823 So, what are the changes? 648 00:36:13,003 --> 00:36:15,403 Well, he sings in a synagogue, 649 00:36:15,805 --> 00:36:18,296 and his voice is certainly different. 650 00:36:19,342 --> 00:36:20,809 My voice is trying to get deeper. 651 00:36:20,944 --> 00:36:25,643 It fluctuates where - kinda depending on where I am with the dose. 652 00:36:25,782 --> 00:36:29,081 It can go farther down when I'm singing, 653 00:36:29,219 --> 00:36:30,709 but my speaking voice can be anywhere 654 00:36:30,854 --> 00:36:34,051 from exactly normal to slightly lower than normal. 655 00:36:36,359 --> 00:36:38,520 And he's also getting much hairier. 656 00:36:38,895 --> 00:36:42,387 I'm getting more body hair and traditionally male patterns. 657 00:36:42,532 --> 00:36:45,330 Hair is coming in on the back of my calfs. 658 00:36:45,468 --> 00:36:47,595 Hair is coming in on the edge of my hands 659 00:36:47,737 --> 00:36:50,467 in a way that never happened before. 660 00:36:51,141 --> 00:36:53,632 I'm starting to get darker facial hair here, 661 00:36:53,777 --> 00:36:56,644 and a little bit more here, some on the sides. 662 00:36:56,780 --> 00:36:57,940 But it's really subtle. 663 00:36:59,015 --> 00:37:00,607 My whole body is changing slightly. 664 00:37:00,750 --> 00:37:02,843 My weight's redistributing; 665 00:37:02,986 --> 00:37:04,351 my hips are getting smaller 666 00:37:04,487 --> 00:37:06,352 and my shoulders are starting to get more broad, 667 00:37:06,489 --> 00:37:08,480 and I am starting to get more shoulder muscles, 668 00:37:08,625 --> 00:37:10,183 which I haven't been working out a lot, 669 00:37:10,327 --> 00:37:12,795 so it's clearly not from what I've been doing. 670 00:37:20,503 --> 00:37:24,166 And those physical changes are having an impact on his running. 671 00:37:25,442 --> 00:37:28,070 He's a full minute faster than when he was a woman. 672 00:37:29,079 --> 00:37:30,376 Exactly 10 minutes 673 00:37:35,552 --> 00:37:38,885 There's no doubt that testosterone can change the body. 674 00:37:39,556 --> 00:37:41,547 But what effect does it have on the brain? 675 00:37:43,326 --> 00:37:45,851 Anyone who spends time with children is well aware 676 00:37:45,996 --> 00:37:49,762 that boys and girls tend to behave differently and play differently. 677 00:37:51,501 --> 00:37:54,129 It's always been assumed that these differences are largely driven 678 00:37:54,271 --> 00:37:56,330 by cultural and social pressures. 679 00:37:56,906 --> 00:37:58,134 But there's mounting evidence 680 00:37:58,275 --> 00:38:00,470 that this doesn't explain everything. 681 00:38:01,511 --> 00:38:05,242 Scientists are only just beginning to understand the role biology plays 682 00:38:05,382 --> 00:38:07,543 in shaping children's behaviour. 683 00:38:12,656 --> 00:38:15,216 There's no question that children themselves know 684 00:38:15,358 --> 00:38:19,886 from a very early age what separates the boys from the girls. 685 00:38:24,634 --> 00:38:27,398 We don't like running, we like being gentle. 686 00:38:27,537 --> 00:38:29,004 We can play rough all the time. 687 00:38:29,139 --> 00:38:32,040 Girls put on make-up and boys don't. 688 00:38:32,175 --> 00:38:33,802 My daddy always drives. 689 00:38:33,943 --> 00:38:35,433 When boys do naughty things, 690 00:38:35,578 --> 00:38:37,375 then we will do naughty things. 691 00:38:42,552 --> 00:38:46,010 Play behaviour fascinates scientists like Melissa Hines. 692 00:38:46,990 --> 00:38:50,016 She's one of the leading figures in a unique long-term British 693 00:38:50,160 --> 00:38:52,526 study following children as they grow up. 694 00:38:57,300 --> 00:39:01,168 The study is examining all aspects of developmental behaviour 695 00:39:01,237 --> 00:39:03,398 and has followed 14,000 mothers and 696 00:39:03,540 --> 00:39:06,008 their children for the last ten years. 697 00:39:10,480 --> 00:39:14,644 And it's uncovered intriguing evidence about biological influences. 698 00:39:15,585 --> 00:39:19,817 The early indications are that testosterone influences play behaviour. 699 00:39:24,694 --> 00:39:29,961 Boys and girls play differently because their brains are sexed differently. 700 00:39:35,205 --> 00:39:37,867 Just like the body, there are parts of the brain, 701 00:39:38,007 --> 00:39:40,066 not the whole brain, but certain parts of it, 702 00:39:40,210 --> 00:39:43,702 that have protectors or receiving units for hormones, 703 00:39:43,847 --> 00:39:45,178 including testosterone. 704 00:39:45,315 --> 00:39:46,646 And in other species, 705 00:39:46,783 --> 00:39:49,343 including non-human primates like rhesus monkeys, 706 00:39:49,486 --> 00:39:53,786 hormones programme development of these brain regions. 707 00:39:55,658 --> 00:39:57,319 If that's the case, 708 00:39:57,460 --> 00:40:00,327 what would testosterone do to a female brain? 709 00:40:01,398 --> 00:40:05,061 Can the apparently cultural phenomenon of the tomboys be explained 710 00:40:05,201 --> 00:40:09,365 by exposure to higher than average levels of testosterone in the womb? 711 00:40:10,273 --> 00:40:14,607 There's some evidence that high levels of testosterone in the womb 712 00:40:14,744 --> 00:40:17,076 are one factor that influences 713 00:40:17,213 --> 00:40:20,205 the development of play behaviour in human beings. 714 00:40:20,350 --> 00:40:21,715 We know, for instance, 715 00:40:21,851 --> 00:40:25,116 that girls exposed to higher than normal levels of androgen 716 00:40:25,255 --> 00:40:28,418 the male hormone - pre-natally, on the average, 717 00:40:28,558 --> 00:40:30,719 show more male typical toy choices, 718 00:40:30,860 --> 00:40:33,522 like to play more often with boys, 719 00:40:33,663 --> 00:40:37,326 and show male typical activity patterns. 720 00:40:39,202 --> 00:40:41,932 If that's true, it will be fascinating to see 721 00:40:42,071 --> 00:40:44,972 what effect testosterone has on Max Toth. 722 00:40:52,482 --> 00:40:54,074 Well, remember six months ago, 723 00:40:54,217 --> 00:40:58,517 Max was tested and had his brain scanned by Doctor Ruben Gur. 724 00:41:00,657 --> 00:41:03,353 Today, Max has come back to be re-tested, 725 00:41:03,960 --> 00:41:07,157 to see if there have been any changes in the way that he thinks. 726 00:41:09,732 --> 00:41:12,428 He'll repeat the tests he did in the brain scanner to see 727 00:41:12,569 --> 00:41:16,733 if the testosterone he's been taking has produced any alterations 728 00:41:16,873 --> 00:41:19,467 in the structure and function of his brain. 729 00:41:24,180 --> 00:41:26,011 The next test is called finger-tapping. 730 00:41:26,149 --> 00:41:27,013 Alrighty? 731 00:41:28,551 --> 00:41:30,815 He'll also repeat the other tests he did 732 00:41:30,954 --> 00:41:33,582 when he was a woman, like finger-tapping. 733 00:41:34,891 --> 00:41:37,155 Men tend to have better motor skills and can, 734 00:41:37,293 --> 00:41:40,285 on average, do more finger taps per minute than women. 735 00:41:41,698 --> 00:41:43,461 Men are also stronger, 736 00:41:43,600 --> 00:41:47,161 and better at manipulating objects in three dimensions. 737 00:41:48,271 --> 00:41:50,501 Women, however, tend to have better verbal skills 738 00:41:50,640 --> 00:41:52,835 and better visual memories. 739 00:41:54,711 --> 00:41:58,203 These are standard scientific tests and will show if, mentally, 740 00:41:58,348 --> 00:42:01,909 Max has become more like a man and less like a woman. 741 00:42:02,051 --> 00:42:09,651 What I would expect to find is improved performance on functions that males 742 00:42:09,792 --> 00:42:12,192 on tasks where males do better, 743 00:42:12,328 --> 00:42:18,460 and worsening performance on tasks where women do better. 744 00:42:18,601 --> 00:42:20,125 I know they've never really studied this before, 745 00:42:20,270 --> 00:42:21,259 and I'm interested to see 746 00:42:21,404 --> 00:42:22,462 if there is any difference because, 747 00:42:22,605 --> 00:42:24,539 you know, I've heard about the androgenising effects 748 00:42:24,674 --> 00:42:25,971 of testosterone on the brain, 749 00:42:26,109 --> 00:42:28,543 so I'm interested to see well, is anything changing. 750 00:42:28,678 --> 00:42:30,771 But I'm fairly dubious that anything will. 751 00:42:34,350 --> 00:42:39,117 The first test measures Max's emotional response to a series of faces. 752 00:42:41,090 --> 00:42:43,285 The machine takes pictures of Max's brain 753 00:42:43,426 --> 00:42:45,621 activity as he looks at faces, 754 00:42:45,762 --> 00:42:48,458 which can then be compared with his emotional response 755 00:42:48,598 --> 00:42:50,862 when he performed the same test as a woman. 756 00:42:52,602 --> 00:42:54,832 The results are startling. 757 00:42:58,942 --> 00:43:00,432 What we are seeing really is a 758 00:43:00,577 --> 00:43:03,410 is a female brain turning into a male brain. 759 00:43:03,546 --> 00:43:08,506 It was quite - quite amazing to see it in a single individual. 760 00:43:09,352 --> 00:43:12,253 This is a scan of Max's brain when he was a woman. 761 00:43:13,056 --> 00:43:15,024 The red areas show which parts of the brain 762 00:43:15,158 --> 00:43:17,558 are used when trying to read emotions. 763 00:43:18,227 --> 00:43:23,062 And this is a scan of Max's brain doing the same task, but as a man. 764 00:43:24,334 --> 00:43:27,929 The more red in the scan picture, the harder the brain is working. 765 00:43:29,005 --> 00:43:29,972 As you can see, 766 00:43:30,106 --> 00:43:31,937 he found it much easier to read emotions 767 00:43:32,075 --> 00:43:34,908 when he was a woman than he does now. 768 00:43:35,044 --> 00:43:39,276 Woman. Man. Woman. Man. 769 00:43:39,816 --> 00:43:44,185 In his case, the second time he had more difficulties with the task. 770 00:43:44,320 --> 00:43:47,448 He had to put in more effort in order to perform 771 00:43:47,590 --> 00:43:50,058 that particular -that particular task. 772 00:43:50,193 --> 00:43:54,425 So his - his brain responds more like a male brain 773 00:43:54,564 --> 00:43:57,556 to the task of trying to distinguish the emotions. 774 00:44:04,807 --> 00:44:07,571 But how did Max do in the practical tests? 775 00:44:11,581 --> 00:44:15,483 All the changes are in the direction that we expected, 776 00:44:15,618 --> 00:44:18,678 in terms of becoming more masculine. 777 00:44:18,821 --> 00:44:21,551 So remember the finger tapping? 778 00:44:21,691 --> 00:44:22,123 Uh-huh. 779 00:44:22,258 --> 00:44:27,286 You managed to squeeze in another three taps per minute. 780 00:44:27,430 --> 00:44:28,454 Whoo-oooh! 781 00:44:28,931 --> 00:44:30,865 Max is also much stronger. 782 00:44:31,701 --> 00:44:35,159 You pushed another four kilos. 783 00:44:35,938 --> 00:44:38,270 So that's -that's a significant... 784 00:44:38,908 --> 00:44:41,934 His spatial awareness has dramatically improved. 785 00:44:42,078 --> 00:44:44,239 Last time you did 75 correct, 786 00:44:44,380 --> 00:44:47,144 this time you did 118 correct. 787 00:44:47,283 --> 00:44:49,410 And that's pretty much the end of the good news. 788 00:44:49,552 --> 00:44:50,246 Right. 789 00:44:50,386 --> 00:44:55,722 Because with becoming a male you also lost a little bit. 790 00:44:56,192 --> 00:44:58,786 Max's visual memory has deteriorated, 791 00:44:58,928 --> 00:45:00,589 and he's not as good with words. 792 00:45:02,165 --> 00:45:03,564 I was actually surprised. 793 00:45:03,700 --> 00:45:10,435 I didn't... I - I was thinking maybe one or two tests will change, 794 00:45:10,573 --> 00:45:13,838 and this is, after all, 795 00:45:13,976 --> 00:45:16,342 a fairly brief period of time. 796 00:45:16,479 --> 00:45:18,845 You would expect changes on those tests 797 00:45:18,981 --> 00:45:22,280 to take place over a longer period. 798 00:45:24,153 --> 00:45:26,348 Max is still sceptical about the extent to 799 00:45:26,489 --> 00:45:28,980 which testosterone has changed his brain, 800 00:45:29,759 --> 00:45:33,525 but acknowledges that it has affected how he feels. 801 00:45:34,831 --> 00:45:36,128 My body is changing, 802 00:45:36,532 --> 00:45:38,557 and it has been surprising to go through that. 803 00:45:38,701 --> 00:45:39,497 It's been, you know, 804 00:45:39,635 --> 00:45:42,069 kind of exciting, and there were changes that I wasn't so, 805 00:45:42,205 --> 00:45:43,797 you know, that I didn't expect to go through. 806 00:45:43,940 --> 00:45:46,841 There was a period of time where I really had trouble crying. 807 00:45:46,976 --> 00:45:49,501 And it felt biological to me. 808 00:45:49,645 --> 00:45:53,081 And by that I mean I've gone through different periods in my life 809 00:45:53,216 --> 00:45:57,812 where I had a harder time crying and had an easier time crying. 810 00:45:57,954 --> 00:45:59,285 And this was the first time 811 00:45:59,422 --> 00:46:01,754 where I felt like I really wanted to cry and, 812 00:46:01,891 --> 00:46:05,122 like, there was something biochemical preventing me from doing it. 813 00:46:05,261 --> 00:46:07,286 Like, it really felt like a big block. 814 00:46:07,430 --> 00:46:10,228 And that was kind of a scary moment for me. 815 00:46:12,835 --> 00:46:15,633 For Max there's now no going back. 816 00:46:16,739 --> 00:46:19,367 As you can see from this time lapse sequence 817 00:46:19,509 --> 00:46:23,639 he's already undergone remarkable changes in just six months. 818 00:46:27,250 --> 00:46:30,549 In another year he will look like this. 819 00:46:36,259 --> 00:46:37,283 Further down the line, 820 00:46:37,426 --> 00:46:42,659 Max might consider having surgery to enhance his masculinity. 821 00:46:43,466 --> 00:46:47,527 But for now, he's happy with what testosterone alone has done. 822 00:46:48,237 --> 00:46:49,397 I'm very excited. 823 00:46:49,539 --> 00:46:52,372 Like, I didn't think I would be that excited about it. 824 00:46:52,508 --> 00:46:54,567 But the way that my body is changing shape, 825 00:46:54,710 --> 00:46:57,679 the way that my fat's redistributing, 826 00:46:57,814 --> 00:46:59,873 that my shoulders are getting broader, 827 00:47:00,016 --> 00:47:02,678 the facial hair, it's really exciting for me. 828 00:47:02,819 --> 00:47:07,085 Like, it's starting to feel much more comfortable for me to be in my body. 829 00:47:07,223 --> 00:47:09,350 And even some of my friends have noticed, 830 00:47:09,492 --> 00:47:12,052 they're, like, wow, you're much more comfortable. 831 00:47:12,195 --> 00:47:13,719 And I just present more comfortable and 832 00:47:13,863 --> 00:47:15,990 more confident because I feel better. 833 00:47:17,600 --> 00:47:19,659 Manipulating sex hormones has allowed 834 00:47:19,802 --> 00:47:22,362 Max Toth to make a choice about his gender. 835 00:47:26,175 --> 00:47:27,767 But science is only just beginning to 836 00:47:27,910 --> 00:47:30,674 explore what can be done to humans. 837 00:47:35,484 --> 00:47:38,282 Manipulating DNA to build super athletes 838 00:47:38,421 --> 00:47:42,255 or even radically redesign humans may be a long way off, 839 00:47:43,192 --> 00:47:47,026 but the future has a way of arriving faster than we imagined. 840 00:47:47,897 --> 00:47:50,229 The question for society in the 21st Century 841 00:47:50,366 --> 00:47:56,703 is no longer what can we do, but how far are we prepared to go. 842 00:48:01,510 --> 00:48:03,637 Next week - ageing. 843 00:48:05,147 --> 00:48:08,082 Thanks to recent advances in molecular biology, 844 00:48:08,217 --> 00:48:12,085 it's now possible to explain exactly why we age. 845 00:48:12,889 --> 00:48:15,722 Scientists have now identified the rogue elements 846 00:48:15,858 --> 00:48:19,123 that cause ageing and have developed drugs that, 847 00:48:19,262 --> 00:48:23,198 for the first time, truly extend life.