Thursday, December 10, 2009

Testosterone in the News

I like testosterone, the fuel of my physical masculinity. Can't imagine life without it. Problem is that this essential hormone has gotten a bad rap over the years, mostly due to feminists reasoning that if men are more violent or aggressive than women (which is only true in magnitude and not so much in frequency), then it must be the male hormone that is causing all the problems. Not so much.

Here is a new article that looks at the power of testosterone in women, with the assumption that it should trigger them to be more aggressive, but in reality they ended up being more fair and concerned with how they were perceived (social status, the lack of which is more associated with violent behavior). Interestingly, the women who got a placebo but THOUGHT they had received testosterone were more antisocial.

Does Testosterone Have a Bad Rap?

By Constance Holden
ScienceNOW Daily News
8 December 2009

Testosterone has a reputation for causing violent and antisocial behavior. But that's a bad rap, according to a new study. Women given the hormone acted more fairly in an economic game than did those given a placebo. Interestingly, however, women in the placebo group were more antisocial if they thought they had received testosterone, indicating that our negative attitudes toward the hormone have a powerful sway on behavior.

Scientists led by Ernst Fehr, a professor of neuroeconomics at the University of Zurich in Switzerland, suspected that testosterone is really about gaining and maintaining social status. And although status concerns lead to aggression, they theorized that testosterone does not necessarily make a person more self-seeking.

The team tested this idea by recruiting 121 women in their 20s to play a game that tests fairness. Two players, A and B, have to agree on the division of 10 money units, in this case Swiss francs. A proposes a division; B can only accept or reject. If B rejects the offer, neither gets any money. All the women were given a dose of either testosterone or a placebo under the tongue. Then 60 women designated as A played the game three times with three different partners, communicating through a computer.

A "fair" offer would be a 50-50 split. So, according to common wisdom, A would make more unfair offers if she were high on testosterone. The status hypothesis predicts the opposite: An unfair offer is more likely to evoke a rejection, which is an affront to A's status. So A is more likely to make an offer that B will accept.

The status hypothesis won. The women given the testosterone made significantly higher offers on average, the group reports online today in Nature: 3.9 francs versus 3.4 francs for the placebo group. "Our interpretation of this finding is that testosterone renders concerns for social status more prominent," says Fehr.

But the results changed depending on what the women believed they had received. Based on questionnaires, the researchers divided the volunteers into women who thought they had received testosterone and those who thought they had received placebo. Those who got the hormone but thought they got a placebo were the most fair; in more than 60% of their offers, they proposed a 50-50 split of the francs. Women who got the placebo but thought they got testosterone were the most unfair; in only 10% of the offers did they propose an even split of the money. That indicates, says Fehr, that the subjects' negative assumptions about testosterone--not the hormone itself--led to antisocial behavior.

Fehr says the group used women because the pharmacokinetics of testosterone doses in women are well-understood. He hopes to do the same experiment with men.

The research should help "demystify the wrong ideas about ... the 'antisocial' hormone testosterone," says Jack van Honk, a neuroscientist at Utrecht University in the Netherlands. But economist Niklas Zethraeus of the Stockholm School of Economics isn't convinced that testosterone influences fairness one way or the other. His group published a study this year using a larger sample that found no connection between sex hormone levels and economic behavior.

Meanwhile, over at Big Think, they took a look at the same research.

Testosterone Poisoning Isn't What You Think

In American folklore, testosterone is supposed to cause rage, lust, competitiveness, nuclear arms races, beer hats and other indicators of whacked-out excess masculinity. Andrew Sullivan, for example, wrote years ago about the "increased edginess and self-confidence'' that he got from hormone supplements--or, as he put it, his "biweekly encounter with a syringe full of manhood.'' He chased sex, he nearly got into fights, he bounced off the walls. Boo-yah!

If matters were that simple, then you'd expect that women who'd taken a testosterone dose before negotiating with each other would be more aggressive and reckless in their tactics.

Not so, says a report this week on the Nature website. Christoph Eisenegger and his colleagues had 121 women play the ultimatum game. Those who received testosterone beforehand were more fair and less egotistical than those who got a placebo.

Actually, there was one group of women who did behave according to stereotype, taking a much more "in-your-face'' stance in the talks. These were the women who thought they had been given testosterone.

Two conclusions: First, this is evidence for Eisenegger's more careful definition of testosterone's effect. He believes it's not a one-note promoter of aggression and lust, but rather a spur to competition for status. The experiment was designed to distinguish between the two theories: if testosterone just impels humans to act like rutting elks, then it should induce bad behavior at the bargaining table. But if it promotes status-seeking, then extra testosterone should be linked to winning the game, not burning down the casino. And so it was.

More importantly, it's a good reminder that we shouldn't assume that "bottom-up'' is a stronger explanation than "top-down'' for people's actions. Many people have an innate bias to think that pills, hormones and brain scans are evidence of forces more real and powerful than ideas, feelings and conversation. That's a bias to watch out for. Testosterone isn't just a chemical; it's an idea about gender and behavior that many Americans have acquired. The chemical can cause behavior changes; so can the idea.

Henrich Caveat: The work was done on 121 young women in a rich nation. It's not definitive (I'm not aware of a lot of cross-cultural work on testosterone's effect). But in creating conditions where the "folk theory'' didn't work, it does dent the notion that testosterone could be "a syringe full of manhood.''

Hopefully, this research will begin to undo some of the negativity directed at men simply we have more testosterone than women. In this study, at least, the perception was much different than the reality.

No comments: