Testosterone makes men impulsive: study

Male hormone, testesterone, hampers decision making and increases impulsive behaviour in men, a new study suggests.Researchers, including those from California Institute of Technology in the US, found that men given doses of testosterone performed more poorly on a test designed to measure cognitive reflection than a group given a placebo.

"What we found was the testosterone group was quicker to make snap judgements on brain teasers where your initial guess is usually wrong," said Colin Camerer, Professor at Caltech. "The testosterone is either inhibiting the process of mentally checking your work or increasing the intuitive feeling that 'I'm definitely right,'" said Camerer.

The study, which is one of the largest of its type ever conducted, included 243 males 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 results show that the group that received testosterone scored significantly lower than the group that received the placebo, on average answering 20 per cent fewer questions



correctly.

The testosterone group also "gave incorrect answers more quickly, and correct answers more slowly than the placebo group," the researchers wrote in the study published in the journal Psychological Science. The same effect was not seen in the results of the basic math tests administered to both groups.

The results "demonstrate a clear and robust causal effect of (testosterone) on human cognition and decision-making," researchers said.

They believe that the phenomenon they have observed can be linked to testosterone's effect of increasing confidence in humans. Testosterone is thought to generally enhance the male drive for social status, and recent studies have shown that confidence enhances status.

"We think it works through confidence enhancement. If you are more confident, you will feel like you are right and will not have enough self-doubt to correct mistakes," Camerer said.

Camerer said the results of the study raise questions about potential negative effects of the growing testosterone- replacement therapy industry, which is primarily aimed at reversing the decline in sex drive many middle-aged men experience.