Women are more likely than men to lie about their sex lives, reveals a new study. Women’s coyness about their sexual behaviour was unveiled by a US study involving a fake lie detector test.

In surveys since the 1960s, men typically report having more sexual partners and than do women – a statistically impossible feat. For example, British men boast an average of 13 partners over a lifetime compared with an average of nine partners for women.

Scientists previously explained this anomaly by suggesting men were exaggerating their tally, while women were understating their total. But now Terri Fisher at Ohio State University and Michele Alexander at the University of Maine suggest that men are in fact more truthful in such surveys.

Women change their answers depending on whether or not they believe they will be caught out not telling the truth, the researchers found. The number of sexual partners a woman reported nearly doubled when women thought they were hooked up to a lie detector machine.


“Women are more sensitive to social expectations for their sexual behaviour and may be less than honest when asked about their behaviour in some survey conditions,” says Fisher, a psychologist. She says women appeared to feel under pressure to meet expectations of being more relationship-orientated and not promiscuous.

Completely anonymous

Fisher and Alexander surveyed over 200 unmarried, heterosexual college students aged 18 to 25.

One group filled in questionnaires having been told the researcher might view their responses. A second group filled in the survey completely anonymously, alone in a room.

A third group had electrodes placed on their hand, forearms and neck and were told they were being attached to a polygraph or lie detector machine – although there was in fact no working machine.

Women who thought their responses might be read said they had had an average of 2.6 sexual partners, compared with 3.4 partners for those who thought their answers were anonymous. But those who thought they would be caught out by the polygraph reported an average of 4.4 partners.

In contrast, men’s answers did not vary significantly. Those attached to the lie-detector reported an average of 4.0 partners compared with 3.7 for men who thought their answers would be read.

The researchers think the results explain the previously reported differences in men and women’s sexual behaviour, with women being afraid of getting labelled as “whores”.

“We live in a culture that really does expect a different pattern of sexual behaviour from women than it does from men,” says Fisher.

Journal reference: Journal of Sex Research: (vol 40, p 27)