How Testosterone Might Affect Your Thinking

Testosterone appeared to increase men’s reliance on gut instincts

Black and white photo of Clint Eastwood: Good, Bad, UglyWhen the likes of Clint Eastwood and Sylvester Stallone are facing off with multitudes of bad guys without batting an eye, what’s going on in their heads could be an effect of testosterone.

Testosterone may reduce men’s ability to question their impulses, according to a new study. In what became the largest-ever testosterone administration study, researchers from Caltech, the Wharton School, Western University and ZRT Laboratory set out to test the cognitive effects of testosterone in men.

These researchers applied either a testosterone gel or a placebo gel to 243 men. Then, they tested them with riddles for which the answer that usually comes immediately to mind is incorrect.

“What we found was the testosterone group was quicker to make snap judgments on brain teasers where your initial guess is usually wrong,” said lead study author Dr. Colin Camerer, of Caltech, in a press release. “The testosterone is either inhibiting the process of mentally checking your work or increasing the intuitive feeling that ‘I’m definitely right.'”

Even though study participants were offered money for correct answers, the men who received the testosterone gel answered around 20 percent fewer of the riddles correctly than the placebo group, this study found. The men who received testosterone also blurted out their incorrect answers more quickly and took longer to give correct answers.

Both groups also took basic math tests, but the study authors didn’t identify a similar effect. That could be because math doesn’t require as much “cognitive reflection” as riddles do. This study defined cognitive reflection as “the capacity to monitor one’s own intuitive judgments and override them when appropriate.” The authors suggested that testosterone may mute cognitive reflection in men.

Dr. Camerer and team said they believe the effect they identified in their study was the result of “confidence enhancement” — a phenomenon described in other recent studies of testosterone.

“If you’re more confident, you’ll feel like you’re right and will not have enough self-doubt to correct mistakes,” Dr. Camerer said.

The increasingly common answer to low testosterone? Testosterone-replacement therapy, which often involves a testosterone gel similar to the one used in this study.

“If men want more testosterone to increase sex drive, are there other effects?” Dr. Camerer said. “Do these men become too mentally bold and thinking they know things they don’t?”

This study was published in the journal Psychological Science.

The MacArthur Foundation, Ivey Business School, International Foundation for Research in Experimental Economics, Russell Sage Foundation, USC, INSEAD, and the Stockholm School of Economics funded this research. The study authors disclosed no potential conflicts of interest.

Psychological Science, “Single dose testosterone administration impairs cognitive reflection in men”
Caltech, “Testosterone Makes Men Less Likely to Question Their Impulses”
Written by: Alex Lindley | Medically reviewed by: Dr. Robert Carlson, M.D.