And we have testosterone.

Here's what we find on testosterone.

But because this individual lacks receptors to hear that testosterone, the body doesn't react to the testosterone.

There's lots of hormones. There's testosterone, adrenalin.

Get your testosterone up. Get your cortisol down.

Normally the testes should make testosterone, the male hormone.

So we, in experiments, have administered testosterone to men.

But we're doing it with a lot less testosterone.

Men have testosterone and are in general physically stronger than women.

Testosterone is another hormone that increases oil production in the skin.

So in the fetal life, those testes are pumping out testosterone.

So lots of levels of testosterone, but no reaction to it.

And men have 10 times the testosterone as women, so men do this more than women we have testosterone that makes us want to punish people who behave immorally.

So what we find is that high power alpha males in primate hierarchies have high testosterone and low cortisol, and powerful and effective leaders also have high testosterone and low cortisol.

There's another way oxytocin is inhibited, which is interesting through the action of testosterone.

Well let it suffice to say that we felt a bit overwhelmed with testosterone.

To make matters worse, Justin is a boy, meaning he's got more testosterone than girls.

lose their testosterone, they're chemically castrated, and they're subsequently feminized because now they're making the female hormone.

When you think about power, people tended to think only about testosterone, because that was about dominance.

So do you want the high power leader that's dominant, high on testosterone, but really stress reactive?

And I have concocted a questionnaire to see to what degree you express dopamine, serotonin, estrogen and testosterone.

But interestingly, high testosterone males are also more likely to use their own money to punish others for being selfish.

But what atrazine does is it turns on an enzyme, the machinery if you will, aromatase, that converts testosterone into estrogen.

Physiologically, there also are differences on two key hormones testosterone, which is the dominance hormone, and cortisol, which is the stress hormone.

If you sleep for four, five hours a night, even for a week, men's testosterone levels drop to the same degree that they would having aged ten years.

And as he had it, even the most restless, distractible, testosterone addled 15 year old Californian boy only had to spend three days in silence and something in him cooled down and cleared out.

And at that time, we did this extraordinary V Day at Madison Square Garden, where we sold out the entire testosterone filled dome 18,000 people standing up to say Yes to vaginas, which was really a pretty incredible transformation.

So we know that in primate hierarchies, if an alpha needs to take over, if an individual needs to take over an alpha role sort of suddenly, within a few days, that individual's testosterone has gone up significantly and his cortisol has dropped significantly.