For decades, even centuries, scientists have been trying to figure out exactly what are the rules of attraction. If the results of a 15-year study carried out by the University of Louisville are to be believed, however, the answers have finally been uncovered. The food of love, it seems, is all in the mouth.
Svelte figures and toned torsos all have their place, says attractiveness guru Professor Michael Cunningham, but ultimately it is the lips that provoke the most desire in those hot on the heels of love.
"When women are looking at men, they are simultaneously looking for sensuality and ruggedness," he says. "The man should look virile, which means that he shouldn't look too sensual, he shouldn't look too feminine. At the same time there should be some hint of generosity and warmth, so medium sized lips are best on men."
Thus, we are told, Brad Pitt and Johnny Depp are lip-a-licous, though Mick Jagger is clearly too mouthy. Kenneth Branagh, meanwhile, is also branded the kiss of death for being too tight-lipped.
The rules are slightly different when it comes to the opposite sex, however, as men are looking for fullness, redness and warmth in the faces of their partners. This is why, we're told, Anne Robinson's zipped-up smackers can't compare with the lips of Julia Roberts, who has a smile that makes men melt.
While Professor Cunningham, who has been working on the science of attraction since the mid-80s, is more than ready to put his money where his mouth is, he does have a warning. "Lips can certainly enhance the attractiveness of an attractive face," he explains, "but they can't always salvage a face that is unattractive."