Just a voice cue can hook a man in love with a woman. But what is the secret? The honeyed pitch is not enough: the man must receive a clear message to be convinced. A British research published in Biology Letters found this during its investigation made on 30 male subjects.

The volunteers had to listen to recordings of 4 women aged around 25 pronouncing the phrase, "I really like you." Based on these recording, without seeing any image of the women, the men had to score the women for attractiveness.

By slightly raising the pitch of the woman's voice, the attractiveness of each woman boosted, and this corresponded with previous researches showing that a high female pitch voice is perceived by men as being linked to youth and fertility. The highest pitches were men's preferred choices, even when the voices' pitch values went over the average.

When the subjects listened to the same woman's voice pronouncing "I don't really like you," this plummeted the the attractiveness of the voice, no matter the pitch. When the negative phrase was played backwards, so that the men could assess just the quality of the voice, the attractiveness marks were boosted once again.

"A clear verbal cue is one of the basket of signals that women can send to get a man to act on his impulses." wrote the authors.

Other available cues a woman can send include a smile, an eye-to-eye look and a pleased expression. Thus, men do not act motivated just by the beauty of a woman.

"The male need for clarity is a residual evolutionary trait. In the mating business, ignoring subtle signals that one is not wanted could be a waste of precious time and energy or worse. The mating effort is a finite resource," said lead author Benedict Jones, a professor at the University of Aberdeen in Scotland,