Testosterone fuels boneheaded decision-making in men, study finds

PASADENA, Calif. — Testosterone-driven men are often portrayed in movies and books as impulsive brutes who don’t waste time talking tense situations through and are more likely to stick with their gut. Now, science explains why: A new study finds that testosterone actually leads men to feel significantly more confident in a rash decision, while spending less time thinking their responses through.

Researchers at a handful of universities, including Caltech and Wharton, conducted an experiment with 243 male participants, hoping to determine whether higher levels of testosterone led men to predominantly rely on hastily-made intuitive judgments.

Each participant was randomly administered either a dose of testosterone or placebo gel before being instructed to take tests measuring cognitive reflection and math skills.

The cognitive reflection test was designed to contain questions with a seemingly-correct intuitive answer that was actually wrong upon further examination. For example, a question might read: “A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball. How much does the ball cost?” Someone solving the question on the fly may be more apt to thinking the answer is ten cents — however someone who took his time to think that response through would then realize the answer is actually five cents, with the bat costing $1.05.

Importantly, the participants were not timed in completing the tasks, and they were rewarded with cash if they answered questions correctly.

The researchers found that the group receiving the dose of testosterone was 20 percent less accurate in answering the questions on the cognitive reflection test than those who received the placebo, answering “incorrect answers more quickly, and correct answers more slowly than the placebo group,” they noted.

There was no demonstrable difference in scores between the two groups on the math test, however.

The basic, arithmetic-based test was administered to try to isolate and validate the effect the researchers believe they would find.

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

For those wondering why a higher level of testosterone decreased scores on the cognitive reflection test, the researchers point to how testosterone is commonly linked to increased levels of confidence.

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

This study presents a possible drawback in pursuing testosterone-replacement therapy, as do many mid-aged men.

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

It’s a question that certainly may point to more future experimentation.

The study’s findings were published in the journal Psychological Science.