Testosterone on the Brain

A new study may shed light on hormones and cognition.

Posted Jun 29, 2017

In 1992, Helen Fisher, an anthropologist at the American Museum of Natural History, wrote an opinion piece in The New York Times extolling the wonders of menopause.  She contended that a menopausal woman’s lower estrogen and slightly higher testosterone levels make her more assertive and aggressive in the workforce. Or as she said, “the biological changes wrought by menopause will bolster their interest in power and increase their ability to use it.”  The piece was headlined “Mighty Menopause.”

For those of us who have gone through menopause, we may not consider ourselves mighty. But aside from the menopausal implications, the article hinted that it was the testosterone that boosted confidence.

So what’s the deal? Does testosterone help or hurt in the workforce? Fisher’s opinion piece from 20 years ago didn’t refer to any scientific studies, though there were plenty of testosterone studies by that time, mainly in rats and dogs. A new hormone study in Psychological Science with a headline-grabbing title, “Single Dose Testosterone Administration Impairs Cognitive Reflection in Men," may shed some light.

The latest study was based on 243 men, mostly college students. About half the men rubbed testosterone on themselves; the rest got placebo gel. About four hours later—when the full impact of the hormone would be felt—they all took a three-question Cognitive Reflection Test. The testosterone-gel group scored 20 percent lower. That is, they were more likely to give the knee-jerk wrong responses.

Here’s one question: "In a lake, there is a patch of lily pads. Every day, the patch doubles in size. If it takes 48 days for the patch to cover the entire lake, how long would it
 take for the patch to cover half of the lake?"

Even if you have no clue about math, you probably realize that the right answer can’t be 24, for the reason that it seems too obvious. But about 20 percent of the testosterone-gel group gave that response—compared to 10 percent of the placebo group.

Gideon Nave, one of the investigators and an assistant professor at the University of Pennsylvania, said the study does not mean that testosterone-laden men are stupider than the rest of us, though one female journalist really wanted to report that. (Not me, by the way).

The research, he said in an email, “links testosterone to intuitive (versus deliberate) decision making.”

Maybe so.

Here’s what grabbed me about the study. I’ve read a trove of testosterone and behavior studies. I’ve heard from friends who say all sorts of things about the impact of their testosterone gel on their personality, which may be wishful thinking. Some credit their daily testosterone schmear with boosting confidence and clearing their aging foggy heads.  (That’s the same thing men said in the 1920s when vasectomies were touted to do that same thing.)

The underlying message of the new study is not necessarily that testosterone makes you jump to the wrong conclusion. I just can’t believe a 3-question survey tells us exactly what this complex hormone does. But here’s what it suggests. It says that this hormone may impact your thinking in ways you really don’t want. And if so, it’s buyer beware. Despite the barrage of advertisements coaxing middle-aged men to rub or inject testosterone, this is one decision you do not want to be impulsive about. If your testosterone is truly low, then sure, bring it back to the normal ranges. But if it you’re looking for a boost of confidence, you may want to try some non-hormonal options.

As for the lily pad question, the answer is 47. The thoughtful (read: non-impulsive) way to do it was to work backwards. If the pond if full on day 48, and if the lily pads double every day, then just one day earlier, the pond would be half full.

As for vasectomies: They don’t boost libido. The 1920s fad faded as most bogus medical claims eventually do.

And as for menopausal women: We are needed in the workforce. Not because estrogen is lower, or testosterone is higher, but just because we’ve got the experience and the know-how. 

For further reading:

Last Sunday, a New York Times opinion piece aptly titled “Men Can Be So Hormonal,” pointed to this study and others that may explain the biological underpinnings. One study found that men with higher testosterone levels had less activity in the frontal lobe, the part of the brain responsible for decision-making.

Watch Nave and his co-investigator deliberate about the study, here’s a link to a video.

And if you want to read a thorough analysis of hormones on the brain: pick up a copy of Brainstorm: The Flaws in the Science of Sex Differences, by Rebecca Jordan-Young.

References

Nave, Gideon, et. al, "Single dose testosterone administration impairs cognitive reflection in men," Psychological Sciences, January 2018