Shania Twain: The perfect face?
Scientists believe they have worked out the dimensions of the most attractive female face.
They say the key to the ideal arrangement of female facial features is the measurements between the eyes, mouth and ears.
Applying their results, the Canadian pop singer Shania Twain was rated as having the perfect visage.
The study, led by the University of Toronto, appears in the journal Vision Research.
The researchers asked students to rate the attractiveness of colour photographs of the same woman's face, laid out side by side.
Using photoshop, the researchers altered the vertical distance between the eyes and mouth, and the horizontal distance between the eyes in each image.
Angelina Jolie does not cut the mustard
The features themselves never changed, just the distance between them, and the woman's face was only compared to her own.
Following a series of experiments, the researchers came up with the most attractive length and width ratios between features.
On length, the distance between a woman's eyes and mouth should be just over a third or 36%, of the overall length of her face, from hairline to chin.
For width, they calculated that the space between a woman's pupils should be just under half, or 46%, of the width of her face from ear to ear.
Fortunately, the researchers calculated that these ratios correspond to an average face.
The researchers said women who did not fit the "perfect dimensions" had no need to resort to extreme measures, such as plastic surgery.
They said hairstyles could be used in effect to create an optical illusion.
Elizabeth Hurley - almost there
Lead researcher Professor Kang Lee said the face of actress and renowned beauty Angelina Jolie did not fit the golden ratio either for length or width.
British actress Elizabeth Hurley scored on the golden ratio for length, and just missed out the width measurement.
Both were eclipsed by Shania Twain, 44, whose hits include Man! I Feel Like a Woman!
The results suggest her face has a perfect set of geometric measurements.
However, the study looked only at white women, and the researchers admit their findings could not be applied to other groups.
Professor David Perrett, of the perception lab at St Andrew's University, said the physical dimensions of a face provided a lot of clues about the health and fertility of the owner.
He said men tended to be attracted to female faces that were young and feminine - probably because they suggested heightened fertility.
But he said the distance between features was probably less important than the appearance of the features themselves.
For instance, a man was likely to be attracted by big eyes, rather than by the fact that they were a certain distance apart.