Testosterone is the most important mile sex hormone men who are heavily influenced by testosterone a said to be egotistical and they 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 is also an expert on whole mines. True feeded you know just astro is responsible for the development of a number of male physical characteristics including hair patterns on the head of it also determines beard growth affects muscles and a mans overall personality as the story gets a much more complex or long term some people might think who often else niggling kuntar. Most testosterone is produced in the testes but a small amount comes from the adrenal cortex. This specific sources of testosterone of a light excels the hormones that are responsible for developing male characteristics in the body are called androgens the most important antigen is 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 immediately after birth. Thus posts yet assigned its hard to say why that happens but it seems to be a part of the matter ration process in the brain tissue and in the male reproductive system does better than my most. Christian of all lives and brawn at the age of 20 he discovered that he had too little testosterone in his body doctors later determined that the cells in his brain were not sending up 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. This fall and. Consequent realizing that something was wrong was a gradual process it didnt happen overnight they kept. Feeling worse and worse at target i have no energy at all and no sex drive either spec ministers money but i could feel something just wasnt right it was a good feeling then i was diagnosed with depression. When i realized that something was seriously wrong with me on how to of can from a little shop and i went right. Home was a medical student at the time and a body build up he kept a close eye on his metabolism and testosterone levels. And was a hoot 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 in its interests of swan so i had some tests done and the levels turned out to be about 0 thats a bit low is in the sense of any. How much testosterone demand actually need. To average men have at least 8. 00 to 12. 00 near normal for a leader of testosterone to anything below that represents a deficiency but the amount also depends on genetics im a single misinformed if you need to womens testosterone levels are much lower food about 5 to 10 percent that ive met. They use the testosterone to synthesize estrogen the primary female sex hormone with the a few. That synthesis is carried out by an insulin called a gram matteis it can be found in cells in several parts of the body including the brain adrenal glands ovaries and testes. In the face of such testosterone levels christiana full chose a potentially risky form of medical treatment. That other kids must set off which i knew i needed hormone replacement therapy after other possible causes like vitamin d. Yours or efficiency have been ruled out it might also be either. One of the side effects of hormone replacement therapy is that it suppresses sperm production which can cause infertility. Just tossed around as naturally produced in the testicles but the process begins in the brain. And the hypothalamus sign and. Hides it links the bodys nervous system to the endurance system to do the pituitary gland. Do you hoof. 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 s. 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. And indeed to sustain the testosterone replacement therapy suppresses the hormones in the pituitary gland that are responsible for sperm production and its like a Birth Control pills and the food in months. And a month but if a man is testosterone deficient and wants to have children we have to take a different approach. Long testosterone can have serious effects on the body but can too much of this whole mind make men overly aggressive. This is leon home the Francis Center for cognitive neuroscience is john cordray or is a Research Director here. Has been studying the influence of testosterone on Human Behavior and hes found little evidence that to stop strong and strokes aggression in men. You feel pretty sure of that that testosterone has on Human Behavior is by no means clear but there is some indirect evidence that you know sample high levels of testosterone have been found in some Prison Inmates whove committed serious crimes these are you more and we did a study which indicated that patients who were given testosterone injections if you could become more aggressive still on the. Show later testosterone can also actually improve social behaviors who. Are some people or literally seem to. So at this point theres little hard evidence pointing to a link between increased levels of testosterone and aggressive behavior. d dreyer conducted an experiment to try to prove or disprove these climbs his 1st task was to measure the testosterone levels in the participants blood. d 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. d before the experiment begins one group of participants is injected with testosterone the other group is given a placebo. d 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 surely looking at us from that event we gave one group of testosterone injections its shores up your mix and recorded the increase in the level of this hormone all. Gone 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 heavy or smaller at this point we observed no difference between the player whod been given testosterone and the one who had it is still into still a sceptic. 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 driver and his colleagues observed a difference between the player who got an extra dose of testosterone and the one who didnt. Seem to be should clean the screw so through its a subtle difference and we confirmed it only in the 2nd stage of the experiment what can you whats. The group administered with extra testosterone imposed a more severe punishment when they believed that they had been given enough money but at 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 was surprised by the results but the situation is more complex than that drama says theres a subconscious motivation at work in. Some of the young. And this manana shows clearly that 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 good leonore. Dreyer has been looking for more evidence to support his theory on the influence of testosterone so hes been studying brain activity. The order that it is to come vocal. Testosterone based behavior can improve a man social status 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 well being like a reward that may explain the boasting trait commonly associated with excessive manly behavior that you know is 20 percent from one to god theres always a motivation behind generosity if someone sees you being generous theyre more likely to think highly of you 020 for example but he said men will probably be more generous if they know that they are being observed by women both we see by them should know by the cube so this indicates another link between testosterone and generous behavior. Lets it has to include we was sure it 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 to start and 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 weekly 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 might be related to other behaviors like helping and prosocial behavior as well the metro has carried out an experiment that involves the ultimatum game similar to the one we saw earlier. 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 carroll address how 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 can use his money to make sure that the other player also profits that will the 2nd player i give back some of his winnings as a gesture of gratitude or would he keep it all for himself. And we found 2 interesting facts 1st its 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 player has reversed 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 across across in a more arguing that in a cooperate environment its again a superstition prosocial behaviors that you gain status and so go in those situations to stutter and actually my prosocial. To is convinced that to stop steroid implies a much more complex role in Human Behavior than research has previously thought through example we can promote socially positive behavior but theres always a motivating factor behind that behavior. Over what. 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 can think of it as process but its also in some definitions an exertion of power. But concepts such as masculinity status and power are perceived differently in various cultures around the world will the test results differ from one country to the next. So of 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 live sex life so my mom didnt think it was funny so i started reading up on my condition it does seem at odds of folks or. Is there a medical solution to infertility caused by testosterone deficiency. Doctors its mom enough has somehow. Been im. Not and licensed and one of the things we can do for men who suffer from this problem is to give them injections of going out on truckin hormones doesnt have a gun to your wrist you could see how p. T. Form of treatment has been used for years even decades where you had seemed and conned. The good nato troop ans include l h which is responsible for the production of testosterone in the testes and if sh which contributes to the production of sperm. The treatment was successful for 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. If i had listened to what the doctors told me at 1st it would have ended right there but now i can have children. All of the szell ties is a professor of psychology at Friedrich Alexander university in erlang and his Research Work focuses on how testosterone affects the body specifically bone growth. Among companies would like. Some effect from just as the one just tossed around an extra die off its counterpart in females and contribute significantly to bone strength and density action from Prenatal Development to maturity. On this an income and in the. Clear example during the 1st 3 months of pregnancy testosterone causes the ring fingers of the male fetus to grow longer than the index fingers in a sling finger. Shows highest notes that in general womens index fingers are longer than they ring fingers in men 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. Because. Testosterone clearly has an influence on bone growth even in the early stages of pregnancy it may also be responsible for the Early Development of the socalled power motive. So this is the as a scientist so im interested in finding out where that motive comes from suspect that its origins can be found in biology is that. 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. And we found that the power motive plays a role in the response to winning or losing. Those who won this had higher levels of testosterone than those who lost everything for the year. And if one of the participants is not motivated 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. Through them tick. 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 business i was not so 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 no 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 at sex differences in the mind between males and females on average and one of tests that we use is where you have to find a shape thats hidden in a design as quickly as you can and we find that on average man are faster at finding target hidden in the overall design. Baron cohen and his colleagues conducted behavioral studies of children and ad lib. 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 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 fluent to take up some of the fluid and we can measure the testosterone in the fluid and babies vary in terms of how much of