When it comes to love, size really does matter, research suggests. For height is the key to sexual attraction.
Only after a couple have decided the difference in height between them is right do they consider face, personality and body shape, it is claimed.
Men prefer to look down on a woman, while women are attracted to taller men.
The scientists have even worked out the ideal proportions - a man should be 1.09 times taller than his partner. This can be expressed as a ratio of 1.09:1.
It suggests that the ideal partner for a 5ft 8in woman is a man who stands 6ft 2in. By contrast a woman of 5ft 2in would seek out a man of around 5ft 8in.
The study by Polish anthropologist Dr Boguslaw Pawlowski, to be published by the Royal Society, suggests we are programmed to choose partners according to this formula.
A man would have to divide his own height by 1.09, and a woman multiply hers by the same figure, to find the ideal, according to the professor's theory.
However, exceptions to the rule immediately spring to mind. Rod Stewart and girlfriend Penny Lancaster, for instance.
Stewart's official height of 5ft 11in appears not only extremely optimistic but incompatible with the statuesque 6ft 1in frame of Miss Lancaster, giving them a far from ideal ratio of 0.97:1.
Anyone applying the theory to 5ft 11in Nicole Kidman and 5ft 7in Tom Cruise, meanwhile, would have been able to predict that their love was doomed.
Their height ratio is 0.94:1. After their divorce Miss Kidman quipped: "At least I can wear high heels again."
Professor Pawlowski, of the University of Wroclaw, said: 'Females prefer taller men. Taller men have higher social status, earn more and are at lower risk from illness.
'They also have better reproductive success, as do shorter women - so a male will look for a smaller female.'
In his study, 600 men and women aged 19-50 were shown outlines of couples of varying heights and asked to say which best represented the ideal.
A majority plumped for those with the height ratio of 1.09:1.
The findings suggest that David Beckham, at 6ft, and his 5ft 7in wife Victoria are an almost perfect match.
But what about exceptionally tall or short people who tend to find partners much shorter or much taller than themselves?
According to the professor, this is down to the unconscious knowledge that they could produce abnormally tall or short children if they married someone of a similar stature.
