YES.

This is why I go to Crossfit so I can lick the TESTOSTERONE off the walls... HAAA!

You know how in college us girrrrls cycle our menses together after living in closer quarters??? Pheromones are potent affectors of hormone synthesis and regulation (upregulation/downregulation). Yes, men are not exempt. P*ssywhipped men really are... sorry dudes... absolutely that's why I encourage my dude to go play POKER/GOLF/GYM/whatever and hang out w/GUYS (I have 2 daughters!)

I think some of that can work in some kind of osmosis. When the testosterone in a group raises, everybody's own testosterone levels raise. In a competitive sports team, the leaders could be the instigators for the others to secrete more testosterone to be on par with the rest of the team.

I also see that being directly confronted with an other male is a good reason for the body to secrete more testosterone. In nature when you confront a male to become the leader or to win a female, testosterone levels ought to go up rapidly.

Competitiveness might be a very strong trigger for testosterone.

But then again:

• Single man's testo. might be higher because they can't stay in a monogamous relationship.
• Men with low testo. are not likely to be interested in the army.
• Criminals might already have higher testo. and this might be what made them do their crime in the first place.

These are just ideas of course.

Competitiveness. It works when around women competing for them, or try to "prove yourself" Infront of men...

There is another possible and very simple explanation. Perhaps men with higher testosterone are more likely to join the military. And perhaps men with lower testosterone are more likely to get married. In fact, I would be surprised if this was not AT LEAST part of the answer if not all of it.

Great question. There are multiple mechanisms through which testosterone can be increased or decreased (i.e. neurochemical, neurobiological, environmental, etc.). Addressing only the social psychological aspects of your question, yes, testosterone (which can affect mood, attitude, behavior, etc.) can increase or decrease depending on one's environment including being around other men (or women). The Stronglifts article you cited link text--which highlights the strength training successes of prisoners, addresses only a small portion of this dynamic. Competition (like Stephen said) is an important environmental variable. But there's more to it. Ironically, in the most unnatural of all human environments, some aspects of prisons can be VERY paleo.The environmental conditions of most men's prisons are very harsh; there are scarce resources, dominant/subordinate hierarchies are extremely pronounced, and survival by affiliation with "like" groups and superior physical strength are all essential advantages for doing time. (Incidentally, the most recent meta-analytic data suggests only a positive, weak relationship between testosterone and aggression). I know that's a bit off topic from your question, Ryan. As for Eva's point --do male groups with higher/lower T levels gravitate towards certain lifestyles--we'd need to have longitudinal (life course) studies that could determine the causal direction. That said--I think there's support for both nature and nurture on this one....

That link has an interesting conclusion on gay mens testosterone, although Id want to read the full report and see other studies before taking their conclusion as fact. As Melissa said, maybe I can use this as an excuse to my girlfriend to get away with the guys more often.

I would be surprised if your hypothesis is incorrect. Makes sense to me.

After men have children, their testosterone may drop to allow them to bond more strongly with their offspring.

All I know is, I was in the military and loved being around mostly guys. There were plenty of women in my squadron, but many times I would look around and realize I was the only woman in the room. What can I say...I make dirty jokes, I'm not a priss, and even though some of the guys might have thought I was "hot," I would never get mistaken for dainty or delicate or a beautiful ballerina.

I was only in the USAF for four years, and even before then, I've always gotten along better with men. My closest/most trusted friends are female, but I tend to have a better time around groups with more guys. (No jokes, please.) No offense, but I find groups of women tend to just be catty, chatty, and...I dunno...I'm an office administrator, and when we have meetings for people to address grievances, make suggestions, streamline processes, etc., when it's all women, it usually winds up being two hours of everyone running their mouths, expressing every last feeling they have -- good and bad -- and nothing ever actually getting accomplished. Maybe that's a product of all meetings (very well could be...I've worked in cubicle hell long enough to know!), but I tend to notice more concrete actions being taken when men are involved.

Maybe I've just known the wrong women most of my life. ;-) Groups of guys seem to be more laid back and don't drive themselves crazy over details in the process of trying to relax and have fun.

I also like working out better around guys. (But then again, I don't do Crossfit, so most of the women at my gym are of the "pink dumbbell" type...tiny weight, tons of bicep curls, or 40 minutes on the elliptical.) I think just being around all that testosterone helps me lift better! ;D (Maybe it raises my own, too?)