The secret to getting a man to tell the truth? Slip him some testosterone, say scientists



Men given gels containing the hormone lied far less in lab tests

Researchers say testosterone's reputation for fuelling aggression may need to be rethought

Testosterone is often associated with aggression and antisocial behaviour.

But it seems high levels of the male hormone, which boosts libido and builds muscle, may make men less likely to lie and cheat.

In a study, scientists boosted the testosterone levels of 46 men by smearing their skin with a gel containing the hormone. Another 45 were treated with a placebo.

High levels of testosterone have previously been associated with bodybuilding and aggressive behaviour - but now researchers believe men with high levels could be more trustworthy.

Both groups were then asked to take part in a behavioural study which involved playing a simple game of dice in an isolated booth. The higher the scores they entered into a computer, the more money they received as a reward.

Neuroscientist Professor Bernd Weber, from the University of Bonn in Germany, said:

'These experiments were designed such that the test subjects were able to lie.

'Due to the separate booths, nobody knew whether they were entering their real scores into the computer, or higher ones in order to get more money.

'However, the scientists were later able to determine if any of the volunteers had been cheating.

'The results, reported in the online journal Public Library of Science ONE, showed that men with boosted testosterone lied less.

High levels of the male hormone have previously been linked to aggressive behavior. Now researchers say it could also make men more trustworthy.

'Test subjects with the higher testosterone levels had clearly lied less frequently than untreated test subjects,' said co-author Professor Armin Falk, an economist also from the University of Bonn.

However, the German scientists were later able to determine if any of the volunteers had been cheating.