Stories tagged testosterone
Curious langurCourtesy John DownerHave you ever wondered why people honk at you .02 seconds after the light turns green? Or why some people take Connect Four a little too seriously? Well, it may be the length of their fingers. That’s right, the difference in length between your 2nd finger (or pointer finger) and your 4th finger (or ring finger) is thought to be an indirect measurement of testosterone levels you were exposed to during fetal development. The more testosterone, the longer your ring finger compared to you pointer finger.
In a recent study, researchers from the University of Liverpool and Oxford used this measurement to link aggressiveness in primates with the levels of prenatal testosterone in utero. They found that Old World monkeys tended to have a low 4th digit (4D) to 2nd digit (2D) ratio (i.e. their ring fingers were longer than their pointer fingers) and also exhibited aggressive, competitive, and promiscuous behavior. New World monkeys (like gibbons), on the other hand, along with Great Apes (like chimps and orangutans) tended to have a higher 2D:4D ratio. These species were found to exhibit much more cooperative and tolerant behavior. The results of the study have implications for our own social behaviors. We live in large multi-male, multi-female groups and are (usually) quite cooperative. This study, and more like it, could start to shed light on the origins of our sociality.
The use of digit ratio as a measurement of prenatal testosterone is not new, however. Many researchers have used it even in humans (we are primates after all) to try and predict various behaviors, aptitudes, and personal characteristics. For example, some of the traits suggested to correlate with low digit ratios (ring longer than pointer) include greater male fertility, assertiveness in women, and greater musical and athletic ability. These studies looked at the increased competitive nature brought out in individuals with exposure to high levels of prenatal testosterone.
So the next time someone cuts you off, just know it might be the case that their 4th digit is longer than their 2nd… so try to leave your 3rd digit out of it.
Tags : Or maybe it just makes you more aggressive, and thus more voracious. Or harder working. Hard to tell.
Cupid's arrow is dipped in neurotransmitters
Kissing chemistryCourtesy David Ball The effect of Cupid's chemicals on my body some 40 years ago are unforgettable. I had so much energy I thought I would burst. I did about 50 pushups trying to relieve the pressure. I couldn't sleep. My pits were secreting overtime. Can you remember the feelings your first love (crush) produced?
The chemistry of love
- Lust is the first of the three stages of love, followed by attraction, then attachment. Lust is driven by the sex hormones testosterone and oestrogen. These hormones "get you out looking for anything". The Science of Love (bbc.co.uk)
- Attraction: By scanning brains of individuals looking at photos of their lovers during that "crazed, can't-think-of-anything-but stage of romance", scientists noted increased blood flow in areas of the brain with high concentrations of receptors for dopamine.
dopamine (is) associated with states of euphoria, craving and addiction. High levels of dopamine are also associated with norepinephrine, which heightens attention, short-term memory, hyperactivity, sleeplessness and goal-oriented behavior. In other words, couples in this stage of love focus intently on the relationship and often on little else. How Stuff Works
- Attachment (or bonding): Being obsessed with ones lover is not compatible with raising children so another love potion is needed. Three chemicals associated with the formation of long-term, monogamous relationships are oxytocin, vasopressin, and endorphins.
"Oxytocin is released during child birth and also helps the breast express milk. Oxytocin is also released by both sexes during orgasm and it is thought that it promotes bonding when adults are intimate." oxytocin.org.
Endorphins, released during physical contact or sex, produce a general sense of well-being, including feeling soothed, peaceful and secure. Vasopressin and oxytocin, also released during sex, are believed to interfere with the dopamine and norepinephrine pathways, which might explain why passionate love fades as attachment grows.
Love is like an addiction
Scientists are discovering that the same chemical process that takes place with addiction takes place when we fall in love. Brain scans of those love crazed individuals in the experiment above showed activity in the same brain area as those using cocaine or nicotine. Similar to other addictive chemicals, the chemical effects of passionate love lose their strength over time, too. After two or three years the chemicals responsible for "that lovin' feeling" (adrenaline, dopamine, norepinephrine, phenylethylamine, etc.) dwindle. Hopefully by then oxytocin, vasopressin, and endorphins resulting from physical intimacy are sufficient to keep the relationship going.
Want to learn more about how love works?
Here is a link to more articles about how love works.
Rocky times for Rambo: Shown here on a promotional tour in 1988 for Rambo III, Sylvester Stallone readily admits that he used HGH and testosterone to beef up his body to look good in his latest Rambo film.Courtesy wikipediaUnlike with professional baseball players, Congressional leaders won’t have to hold hearings on this. Sylvester Stallone is being totally up front and candid about his chemical use to prepare for his latest “Rambo” movie.
The 61-year-old movie star admits that he used human growth hormone (HGH) and testosterone to pump himself up for the new feature film. Regardless of the quality of the movie (and I think I’ll be passing on it even when it hits the dollar theaters), doctors aren’t giving him a thumbs up on that medical decision.
More government studies are being conducted on the use of these substances and they’re not ready of general use, many doctors warn. And past research has shown that HGH and/or testosterone use can increase your risks for diabetes, arthritis, heart disease and possibly cancer.
On top of that, HGH and testosterone are illegal for use in general fitness. Doctors must prescribe the treatments, and only after conducting tests that show a patient’s body is under producing the chemicals.
It’s illegal a lot of other places to, which Stallone found out in producing the movie. Australian officials fined him $10,000 last May when they found him bringing 48 vials of the substances with him into the country for on-location filming.
Through all of this, Stallone seems to have given some conflicting accounts of why he’s used the substances.
Dealing with the Australian legal authorities during court proceedings for possession of HGH and testosterone, Stallone said: “I made a terrible mistake. Not because I was attempting to deceive anyone but I was simply ignorant of your official rules and I wish to sincerely apologize to the court and the Australian community for my breach of Australian customs law. ... I have never supported the use of illegal drugs or engaged in any illegal activities in my entire life. ...I wish to express my deepest remorse and again apologize for my actions.”
But this month in Time magazine, he’s quoted as saying: “Testosterone to me is so important for a sense of well-being when you get older. Everyone over 40 years old would be wise to investigate it because it increases the quality of your life. Mark my words. In 10 years it will be over the counter.”
We’ve walked this path before a few times on the steroid debate over baseball player Barry Bonds. But here’s one more thing to mull over on this latest twist to chemical enhancements to the body. Researchers say HGH and testosterone can certainly make your body look stronger, especially in the way that they help reduce body fat content to give muscles a more “ripped” look. They also allow muscles to recover faster from intense workouts. But there’s no data that says that they’ll make muscles stronger or performer better when being used.
So is it really worth all the medical risks? Is it worth breaking the law to look good? Share your thoughts here with other Science Buzz readers.
Rodney Dangerfield: The late, great comic's use of self-deprecating humor may have been a clever strategy to keep himself out of the breeding pool.Courtesy Mark RyanA British professor has come to the conclusion that humor may be linked to the male hormone testosterone.
Professor Sam Shuster, of Norfolk and Norwich University Hospital, came up with the idea of riding his unicycle around town and tracking the various reactions he received from bystanders.
Men, it seems, mostly jeered and made jokes at his antics, while women made more encouraging comments.
“The difference between the men and women was absolutely remarkable and consistent," Professor Shuster said. He added that the most aggressive taunts came from young men.
During his yearlong study, Shuster rode his unicycle through the streets of Newcastle on Tyne, documenting some 400 reactions. The sight of a man on a unicycle was apparently something new to the region.
Three-quarters of the male comments seemed to come in the form of comic put-downs and snide remarks, and other aggressive behavior cloaked in comedy. On the other hand, reaction from adult women was almost entirely (95%) supportive.
The response from young pre-pubescent children - both boys and girls under 10 - was one of simple curiosity. From puberty to their late teens the girls showed indifference or at best minimal approval. But those boys who had just reached puberty were suddenly a bit more aggressive in their taunts, and even tried to physically knock Shuster off balance.
"At 11-13 years, the boys began to get really aggressive. Into puberty, the aggression became more marked, then it changed into a form of joke,” Shuster said.
The most aggressive of the lot were young men in cars who would roll down their windows and verbally abuse Shuster with belittling ‘jokes’. It could be they perceived Shuster’s unicycling as something that could potentially draw female attention away from them.
"This would be particularly challenging for young males entering the breeding market and thus it does not surprise me that their responses were the more threatening." Dr Nick Neave, a psychologist at the University of Northumbria.
But as men moved into adulthood, the aggression became cloaked in a more repetitive and sophisticated style of humor, which later seemed to fade away, resulting in the aging males becoming verbally more encouraging of Shuster’s cycling, just like their female counterparts. The professor thinks testosterone is at the bottom of it all.
Testosterone is the primary male sex hormone but is present in females as well. The hormone is secreted primarily in the male testes and female ovaries and plays a role in the body’s overall well-being, immune system, energy, and of course the male sex drive. A small amount comes from the adrenal glands in both sexes, but on average an adult male produces eight to ten (one source said up to twenty) times more than an adult female. However, the amount ranges so widely for people that the high end of the female range can overlap with the low end of the male range. The relatively small amount generated by females is used to produce the female hormone estrogen.
Shuster said genetics could explain the differences in reactions across the sexes, but not the rise and fall of the male response. He concluded that testosterone had to be the source of the derived humor.
LINKS
Story on BBC.com
Testosterone and health
All about humor
Some Rodney Dangerfield jokes (move the spotlight to his face)
