This week’s This American Life radio program on NPR is devoted to the topic of testosterone. In addition to first person accounts of life at low and high testosterone levels, the show features a contest (Called Contest-tosterone – cute!) in which the program’s staff members have their testosterone levels measured and then try to predict the results according to the personality characteristics of the participants.
The results of the contest surprise everyone. The male with the highest testosterone levels is “a slightly femmy” gay, and the woman with the highest levels is 5 months pregnant.
Ira Glass, the show’s host, then concludes that the test was a dumb idea, because knowing their testosterone levels changed how members of the staff felt about themselves and each other. The men with low levels felt they were less manly, and the woman with the highest level felt “really bossy and aggressive”.
Well, Ira, I agree. The contest was a dumb idea. But not for the reasons you state.
Why the Contest was a dumb idea
Comparative testosterone levels, especially saliva levels, are meaningless in the normal range.
Number one, testosterone levels are not even replicable between labs.
Number two, testosterone levels fluctuate within the same individual, especially in women during the menstrual cycle.
Number three, saliva testosterone levels say nothing about testosterone levels in the brain, which is the place you seemed most interested in noting its effects.
And finally, circulating testosterone is just a piece of the picture. There are enzymes that activate testosterone, enzymes that convert testosterone to estrogen and hormone receptors whose activity is regulated by testosterone. All of these things affect a hormone’s activity in the body as much as overall levels do. So trying to describe a person by their testosterone levels is like trying to describe the Mona Lisa by measuring how much paint Da Vinci used.
But most importantly, the reason the contest wasn’t such a great idea was that the number of individuals was far too small to make any statistically meaningful conclusions regarding tesosterone leves. The contest’s results were destined to be meaningless from the start.
Bottom Line
Ultimately, at the extremes, testosterone levels can carry meaning. A woman with a sky-high level virilizes. A man without any testosterone is impotent. And in an individual, variations in one’s own levels can have an impact, as the first person stories in the program showed.
When large groups of individuals are compared, some meaning can be found in comparative tesosterone levels (perhaps). But trying to find meaning comparing tesosterone levels in a small group of people is a pointless exercise. Not to mention confusing for the public who listen to This American Life.
By the way, pregnancy raises testosterone levels. Check Julie’s levels again in 6 months while she’s breastfeeding and her levels will be much lower. But I’ll bet she’s still bossy…
Decided to be nice and bite my tongue. Thanks for the post.
I think you did a nice job with this. Brought out points any news outlet should be stumbling over themselves to report. (Did they?)
In fact, I did hear one segment of this show.* I was driving in the car and flipped the radio to hear what sounded like a man saying how he couldn’t think of anything but sex, and womens’ breasts&butts. And then saying that testosterone increased his interest in math and science. And then everyone laughed at how it was a stereotype. But, I felt, just as in politics, you get an idea out and propagate it just by getting it aired. And even if it can be intellectually shot down … some people will still believe it (e.g. the Swift Boat ads.) I didn’t like the segment.
Anyway, loved your post!
* The story about the woman who became a man.
RL –
No need to be nie here 🙂
Bix-
I know. I was shocked ot hear what they were saying. NOne of them has any real knowledge about the topic, and yet they did a whle program on it. The only “expert” they talked to was the one selling them the saliva testing. I was disappointed to say the least.