Testosterone is the most important mile 6 hormone men who are heavily influenced by testosterone a said to be egotistical and i enjoy taking risks but a number of european scientists have been trying to find out whether testosterone is really as bad as its reputation. Weve come to the months to University Hospital to talk to talk to michelles its man a german specialist in the treatment of diseases that affect men hes also an expert on hormones. Just as to what was true feeded you know just astro is responsible for the development of a number of male physical characteristics including hair patterns on the head bowed head also determines beard growth affects muscles and a mans overall personality just as to when its a much more complex or long term some people might think. Most testosterone is produced in the testes but a small amount comes from the adrenal cortex. The specific sources of testosterone of alighting cells the hormones that are responsible for developing male characteristics in the body a code androgens the most important androgen testosterone. Levels of testosterone rise dramatically during puberty and then remain at a high level but researchers have also found significant short term increases in this home and immediately after birth. Home thus past a sign of its hard to say why that happens but it seems to be a part of the maturation process in the braille and in the male reproductive system theres theres a modest. Christian of all lips and brawn at the age of 20 he discovered that he had 2 little testosterone in his body doctors later determined that the cells in his brain were not sending out the proper production signals the cause of the problem wasnt clear. At 1st both had a hard time even describing the symptoms it took a long time for doctors to come up with a proper diagnosis. As far. As concerts were realizing that something was wrong was a gradual process so it didnt happen over night. Feeling worse and worse at target i had no energy at all and no sex drive either and this doesnt but i could feel something just wasnt right it. Could feel that i was diagnosed with depression cops were going i realized something was seriously wrong with make us all hearts of corn from other shops and i went back to the street next. Wholefoods a medical student at the time and a bodybuilder he kept a close eye on his metabolism and testosterone levels. And was approved but i couldnt figure out what was going on i got along well with my family and had a girlfriend i was doing well at school and then i figured out that this might have something to do with a testosterone deficiency i was going to interest as one so i had some tests done and the levels turned out to be about 0 thats a bit low isnt a sense of any. How much testosterone demand actually need. To average men have at least 8. 00 to 12. 00 normals for a leader of testosterone to anything below that represents a deficiency but the amount also depends on genetics a single missing from that you need to convince testosterone levels are much lower food about 5 to 10 percent that of menses they use the testosterone to synthesize estrogen to the primary female sex or not. That synthesis is carried out by an enzyme called a gram it tastes it can be found in sounds in several parts of the body including the brain adrenal glands ovaries and testes. In the face of such testosterone levels christian fold chose a potentially risky form of medical treatment. Will soon have a kid i knew i needed hormone replacement therapy after other possible causes like vitamin d. Or of zinc deficiency have been ruled out. But i was also. One of the side effects of hormone replacement therapy is that it suppresses sperm production which can cause infertility. Most of us. Were just tossed around as naturally produced in the testicles but the process begins in the brain sort of civically in the hypothalamus sign and. Hides it links the bodys nervous system to the end the Current System who the pituitary gland tried to do you who. The picture trick land is divided into 2 sections the anterior portion produces 2 key hormones l. H. And s. And each l. H. Is responsible for stimulating the production of testosterone in the testes if as h. Contributes to the production of span. These 2 hormones report back to the brain on whether the body is producing enough testosterone and spurn. The brain adjusts the amounts of each as necessary. The need to store even testosterone replacement therapy suppresses the hormones in the pituitary gland that are responsible for sperm production and its like a Birth Control pill and the pill or food in months. And among others but if a minister starstruck deficient and wants to have children we have to take a different approach. Low testosterone can have serious effects on the body that can too much of this whole mind make men overly aggressive. This is leon home of france the center for cognitive neuroscience is john cole dreher is a Research Director here. Has been studying the influence of testosterone on Human Behavior and hes found little evidence that to stop strong stocks aggression in men. That is surely a vector that testosterone has on Human Behavior is by no means clear but there is some indirect evidence and the 3rd sample high levels of testosterone have been found in some Prison Inmates whove committed serious crimes to these are you more and we did a study which indicated that patients who were given a testosterone injections if you could become more aggressive still on the 50 minute call to show new that was testosterone can also actually improve social behaviors who. Are some group or naturally the seem to. So at this point theres little hard evidence pointing to a link between increased levels of testosterone and aggressive behavior. Ready dreyer conducted an experiment to try to prove or disprove these clients his 1st task was to measure the testosterone levels in the participants blood. Ready ready testosterone is a fat soluble hormone so it can pass through the membranes of cells bind with hormone receptors and then produce changes in the cell structure. Testosterone can be identified and measured in various bodily fluids. Including saliva urine and blood. Before the experiment begins one group of participants is injected with testosterone the other group is given a placebo. Ready group and we tried to determine whether the increase in testosterone levels would contribute to a change in behavior as you as graph shows that both groups started out with approximately the same level of testosterone goes to ensure that is then we gave one group of testosterone injections is to once again he said and recorded the increase in the level of this hormone all. Of them. Now the test subjects are going to take part in a game exercise called ultimatum the game is frequently used in Behavior Research its designed to test whether a person is generous all selfish one of the players is given a sum of money and is required to share part of that with the other if the 2nd player accepts the offer the deal goes ahead as planned but if he rejects it neither player gets any money. From those of us more at this point we observed no difference between the player whod been given testosterone and the one who hasnt is still. A setup. Now the rules of the game are going to change a bit the players will be able to use the money to reward fair behavior or punish unfair behavior and this is where dre and his colleagues observed a difference between the player who got an extra dose of testosterone and the one who didnt. See of obesity in this group so through its a subtle difference and we confirmed it only in the 2nd stage of the experiment what can you what. The group administered with its extra testosterone imposed a more severe punishment when they believed that they had been given enough money not in the same time they also reacted more positively when given more money than expected he did you know. We observed a big difference in the behavior of the 2 groups. So can testosterone also stimulate generosity in men the researchers were surprised by the results but the situation is more complex than that dre a says this is subconscious motivation at work here. So much of young show you know. This man aman and shows clearly. And you can improve your social status if you cooperate with people or engage in other kinds of positive social behavior. So more so while testosterone can influence aggression commitments which it also plays a role in the ability to act with generosity so thats been really annoys. Dreyer has been looking for more evidence to support his theory on the influence of testosterone so hes been studying brain activity. That is 2 or more testosterone based behavior that can improve a mans social status report and that process could be linked to various mechanisms in the brain in a particular way a group of neural structures known as the reward system to mark. Improved social status generates a sense of wellbeing like a reward that may explain the boasting trait commonly associated with excessive manly behavior that you know is to supersoaker more not to go there is always a motivation behind generosity if someone sees you being generous theyre more likely to think highly of you for example she said men will probably be more generous if they know that they are being observed by women 20 simply by some children by a long job so this indicates another link between testosterone and generous behavior. Let this was to impose we will see ensure that was to. So testosterone may be responsible for positive and negative behavior in both cases this behavior seems to be directed at preserving or even improving social status. Psychologist pronto mehta is an associate professor at University College in london. His research focuses on how hormones particularly testosterone influence Human Behavior. The evidence for that myth that testosterone is directly related to masculine traits like aggression has not borne out in the data so there are plenty of results suggesting that testosterone is either weakly or unrelated to aggressive behavior at all in humans including human males so the field is still trying to unpack these kinds of the facts to understand when to start or might be related to other behaviors like helping and prosocial behavior as well. Mettle has carried out an experiment that involves the ultimatum game similar to the one we saw early on. Its actually a way to look at 2 kinds of behaviors one is trust to what extent is the 1st mover trusting and 2 to look at reciprocity of trust if someone is hyper trusting is the 2nd mover going to reciprocate that trust. As in the experiment carried out by sean dreyer one player was given an extra dose of testosterone the other player was given a placebo. The experiment will measure the level of trust between the 2 the player administered testosterone could use his money to make sure that the other player also profits but will the 2nd player give back some of his winnings as a gesture of gratitude or would he keep it all for himself. But we found 2 interesting facts 1st is consistent with the stereotype testosterone reduce trust in the 1st mover so that is somewhat consistent with the stereotype testosterone being related to. Competitiveness and threat and the environment and maybe. Mobilizing more selfish social behaviors rates are going to keep money. Next the players reverse their roles. In both tests the player with the extra testosterone shares his winnings with the other this is an example of pro social behavior. We know that reciprocity even cooperate of situations where its going to garner status and what we found is it has offered to sit reciprocity more arguing that in a cooperate of environment its again a superstition prosocial behaviors that you gain status and so though in those situations its a starter and actually my prosocial. Mehta is convinced that testosterone plays a much more complex role in Human Behavior than research has previously felt for example he can promote socially positive behavior but theres always a motivating factor behind that behavior. Over life. You can imagine when we think about our leaders and people in positions of power they have expertise knowledge and experience that theyre going to relate to their subordinates thats part of being a good leader thats also part of some definitions of power where youre helping others as a way to influence others in some ways so you could think of it as process but its also in some definitions an exertion of power. But concepts such as masculinity status and power are up to see differently in various cultures around the world will the test results differ from one country to the next. So my laboratory isnt one in someone elses laboratory in germany someone elses laboratory is in a rural part of the south of the United States that should theoretically be expected to change the results. But the effects of testosterone on the human body at the same regardless of culture and geography when Christian Vall found out that he was infertile he started looking for solutions. But my mother took me to see a urologist and he told her that i would never have children or that i could have a super lot of sex life so my mom didnt think it was funny so i started reading up on my condition it was in a stream of bytes of folks or. Is there a medical solution to infertility caused by testosterone deficiency. Doc does it smart enough to somehow. Not want that something and one of the things we can do for men who suffer from this problem is to give them injections of going out or dropping hormones so they have a gun during your happy form of treatment has been used for years even decades where you dont seem to come. The good night or trope ans include l h which is responsible for the production of testosterone in the testes and if s. And each which contributes to the production of sperm. The treatment was successful christian of all for his body was able to produce testosterone and fish sperm for a short period of time he had the sperm frozen for later use. He starts to listen to what the doctors told me at 1st it would have ended right there but now i can have children. One of the szell times is a professor of psychology at Friedrich Alexander university in a long and his Research Work focuses on how testosterone affects the body specifically bone growth. Companies would like to go and do some effective from. Just asteroids and extradite its counterpart in females and contribute significantly to bone strength and density engine from Prenatal Development to maturity of your own to see incumbents in the. Clear example during the 1st 3 months of pregnancy testosterone causes the ring fingers of the male foetus to grow longer than the index fingers in the sling fingers. Show types notes that in general womens index fingers are longer than they ring fingers in many its just the opposite. Here you can see that in this image of a mans hand. Index finger is clearly shorter than the ring finger that. Goes because. Testosterone clearly has an influence on bone growth even in the early stages of pregnancy it might also be responsible for the Early Development of the socalled power motive. So this as a scientist so im interested in finding out where that motive comes from i suspect that its origins can be found in biology. Here is conducting an experiment in which the participants write a fantasy narrative this may help them to determine whether they are motivated by power. Or the power motive is a common human characteristic that involves one persons efforts to have an impact on the behavior of others this motivation does not necessarily manifest itself in conscious attitudes or the beliefs that we have about ourselves our Research Indicates that the way we perceive ourselves actually has little to do with what makes us tick and what influences our spontaneous behaviors. In. This part of the experiment involves a series of 10 tests and finding out how the participants respond to victory or defeat. The test results can be manipulated one participant can win up to 8 of the 10 rounds. The researchers want to find out whether any changes take place in the test subjects hormone levels. We found that the power motive plays a role in the response to winning or losing. Those who once had higher levels of testosterone than those who lost 3 of them for the year. And if one of the participants is not much of a suit by power but wins it has no effect on the amount of testosterone in his system. We cant say that winning or losing is exclusively responsible for changes in testosterone levels we have to take into account factors such as the individuals personality and motivation. For. Those factors are shaped by testosterone during fetal Brain Development. But does it all come down to testosterone and its influence in determining for example male think the length and the development of the power motive. Women have only 10 percent of the testosterone levels found in men does that mean that they are less motivated by power. By play theres no evidence that indicates that there is a connection between the length of womens fingers and the power motive complex. Its a complex situation that will require a lot more research. Scientists have learned more in recent years about female sex hormones but the relationship between women and power has not been widely studied. The field has focused on male reproductive system and males for the past 100 years and has largely in their collective looking at female sex hormones in the context of status and leadership and this is. This is a large gap in the literature today. Weve come to the university of cambridge to talk to clinical psychologist simon baron cohen. Part of his research focuses on how gender affects Human Behavior in general and the brain in particular. Weve been looking sex differences in the mind between males and females on average and one of the tests that we use is where you have to find a shape thats hidden in the design as quickly as you can and we find that on average man are faster at finding this target hidden in the overall design. Baron cohen and his colleagues conducted behavioral studies of children and adults. Since they started by testing hormone levels in numerous samples of amniotic fluid the liquid that helps protect the fetus in the womb. Weve measured the testosterone during the pregnancy in the womb in the amniotic fluid so this is the baby in the womb and some women during pregnancy have a clinical procedure called amniocentesis where a needle goes into that fluid to take out some of the fluid and we can measure testosterone in the fluid and babies vary in ter