How testosterone gives men gift of the gab

Men with relatively high levels of testosterone not only have a greater sex drive but also benefit from increased powers of persuasion, new research indicates.

The link between smooth-talkers and testosterone - the male sex hormone - has surprised academics, as improved verbal fluency has been previously associated with oestrogen, the female hormone. Researchers from the University of Manchester found that men who had been given weekly injections of testosterone were 20 per cent more fluent after a month on the hormone.

The findings have important implications for "hypogonadal" men who are born with low or no levels of testosterone, as well as those who would take the male contraceptive pill, which involves increasing levels of testosterone in the body, the researchers said.

Dr Daryl O'Connor, a co-author of the study, said: "Previous research has shown that men outperform women on spatial ability, such as map reading, and women outperform men on verbal ability. It is a well-known gender difference. The fact that higher levels of testosterone improved men's verbal fluency was unexpected and these findings give us a preliminary insight into the non-sexual benefits of the hormone."

The World Health Organisation study was presented at the British Psychological Society's annual conference in Winchester yesterday.

The researchers recruited 30 men, aged 18 to 40, and gave them weekly injections of either 200mg of testosterone or a saline placebo. The men took computerised tests for verbal fluency, spatial ability, motor co-ordination, memory and attention.

Men who were on the testosterone injections had double the level of testosterone in their bodies at four weeks and performed 20 per cent better on the verbal fluency test. However, their natural spatial skills reduced with increased testosterone.

Dr O'Connor said: "This result tends to suggest there may be an optimal level of testosterone for men. Additional levels may not bring added benefits. This is a preliminary piece of work and it is based on a reasonably small sample. [But] it is worth investigating ... Testosterone may have unexpected benefits on some aspects of non-sexual behaviour in men."