Testosterone, a popular supplement for men worried about maintaining their vigor, should actually make men worried about maintaining something else: good judgement. Researchers at Caltech are convinced that higher levels of testosterone increase the tendency in men to rely on their intuitive judgments and reduce cognitive reflection. The researchers found that men given doses of testosterone performed worse on a test designed to measure cognitive reflection than a group given a placebo. A CalTech news release reports that the study involved 243 men who were randomly selected to receive a dose of testosterone gel or placebo gel before taking a cognitive reflection test. A math task was also given to control for participant engagement, motivation level, and basic math skills.
The questions included on the cognitive reflection test are exemplified by the following:
A bat and a ball cost $1.10 in total. The bat costs $1 more than the ball.
How much does the ball cost?
For many people, the first answer that comes to mind is that the ball costs 10 cents, but that’s incorrect because then the bat costs only 90 cents more than the ball. The correct answer is that the ball costs 5 cents and the bat costs $1.05. An individual prone to relying on their gut instincts would be more likely to accept their first answer of 10 cents. However, another person might realize their initial error through cognitive reflection and come up with the correct answer.
The researchers found that the group that received testosterone scored significantly lower than the group that received the placebo, on average answering 20 percent fewer questions correctly. The testosterone group also “gave incorrect answers more quickly, and correct answers more slowly than the placebo group.”
What’s up with that? The researchers think that testosterone increases confidence in humans, and confidence is sometimes the enemy of common sense.