It looks like women are more complicated than we thought, says Cian O'Luanaigh . Their preference for silver-tongued men with deep voices is dependent on the pitch of their own voices

It's not easy choosing a guy. Do you go for the big man with the deep voice, strong jawline and pugnacious streak, or the nice sensitive chap with the squeaky voice who'll take good care of you, but then run away when there's a fight in the offing?

Researchers at Aberdeen University have confirmed that women are attracted to guys with deep voices – as long as they say nice things. But it seems a woman's preferred pitch in a man's voice depends on the pitch of her own voice.

The researchers measured the average voice pitch of 113 heterosexual female undergraduates as they spoke vowel sounds, read a standard sentence and a standard passage of text.

The women then listened to recordings of four men saying either "I really like you", or "I really don't like you", and scored their preferences. The voice recordings had been digitally altered to sound more masculine or more feminine by increasing or decreasing their pitch.

The women generally preferred deeper "masculinised" voices to the higher-pitched, more "feminine" recordings. But when the men were saying "I really like you", it was the women who had the highest-pitched voices who had the strongest preference for men with deep voices.

When the statement was "I really don't like you", the relationship between the woman's own voice pitch and her preference disappeared.

So women aren't just attracted to a deep voice, lads. You have to say nice things too.

The preference didn't depend on the woman's age, what point she had reached in her menstrual cycle or whether she was on the pill.

"We have shown in previous studies that women's voices with relatively high pitch tend to be judged as attractive," said Ben Jones of Aberdeen University's Face Research Lab, who led the study. Voice pitch indicates a woman's average oestrogen levels and so might be a cue advertising her health and fertility. The pitch of a woman's voice is highest at ovulation and her preference for men with "masculine" traits is also at its greatest.

Previous research at the Face Research Lab has shown that women perceive lower male voices to be more masculine. "Our new research shows that women with attractive voices have particularly strong preferences for masculine men," said Jones.

The researchers suggest that it may be adaptive for a woman with a high-pitched, attractive voice to prefer deep male voices because she may be more able to attract and hang onto a masculine partner than women with lower, less attractive voices.

The study is published in the current issue of Behavioral Ecology.

"If females prefer men with low voices, that suggests the pitch of the voice gives some sort of indication of the underlying quality of the men," said Dr Alan McElligott of Queen Mary, University of London, "but the exact link between quality of the men and pitch of the voice is not known."

McElligott studies vocal communication in fallow deer, where the females prefer males with deep calls. "Doing this on human speech is very complicated," he said, "but if you compare humans to other large mammals there are lots of similarities"

It used to be thought that voice pitch in mammals relates to body size, but that is no longer believed top be the case. McElligott pointed out that you can have big men with higher-pitched voices, or smaller men with lower-pitched voices, so pitch is not always an indication of body size.

The pitch of a man's voice also changes with stress and in response to the prevailing social hierarchy. But pitch does give females some sort of cue to the quality of males.

"It's tempting to think that differences among people in the types of individuals that they find attractive and unattractive are simply due to rather random aspects of personal taste," said Jones. "But this work, along with a lot of other work that we have published over the last few years, shows that at least some of this personal opinion can be predicted by, for example, measures of women's own attractiveness."

It seems the finding doesn't just apply to young women in Aberdeen. Jones said previous studies, testing thousands of women on the internet, showed a similar relationship between women's beliefs about their own attractiveness and their preferences for masculine characteristics in men's faces.