The reason you prefer Zac Efron to Arnie or why you're always drawn to the nervous-looking fellow in the club is not pure passion, but does have a scientific basis.
Why we fall in love
It's no surprise to scientists that the likes of Zac Efron and Johnny Depp get women's hearts racing. According to a study of secondary school children, girls in single-sex schools display a strong preference for feminine features. Hooray for the metrosexual male!
The scent of a woman is more powerful than we first thought. A US study involving a good deal of T-shirt sniffing revealed that a man's testosterone levels are higher when they get a whiff of an ovulating woman – worth knowing when you're planning a night out.
It has long been said that opposites attract but a recent study by anthropologists has confirmed the theory. By choosing a mate who is genetically dissimilar to ourselves, we increase our chances of strong, healthy babies. It explains Bernie Ecclestone's appeal – Brad and Angelina must be the exception to the rule.
It might mean you're safe from unwanted pregnancies but the Pill actually changes the type of man we're attracted to. One study found that women on the contraceptive pill chose men who had pronounced masculine features (also a sign of high testosterone levels and aggressive behaviour). Perhaps try condoms first.
Going high-pitched and giggly if you're looking to impress is a definite no-no. Scientists in Pennsylvania recently discovered that both men and women found the opposite sex infinitely more attractive when they adopted a deep, husky tone. Time to brush up that Lauren Bacall impression...
From boobs to feet, we know we're not perfect. But the more symmetrical the face, the more attractive it becomes because subconsciously, we're thinking 'good genes'. And according to scientists we girls are more likely to achieve orgasm with a symmetrical partner – now that's worth knowing.
Forget the strong, independent type – recent research revealed that we ladies just can't resist a man 'in danger'. Male antelopes have been found to put on a fake danger signal in order to confuse the females and grab sneaky shot at mating. Beware the nervous fellow at the bar – it may be a cunning ruse.
Few of us would admit that a monotonous voice is what really gets us going. But apparently the sound of a "steady" monotone man's voice is simply irresistible. Researchers say it indicates authority and independence – and that means higher status. Try digging out those old Clint Eastwood westerns and test the theory...
If you're aiming for that size zero look you'd better think again. It turns out that curvy girls give the guys a natural high. In fact, when faced with womanly hips, bums and boobs, the male brain lights up, just like it would if he'd been indulging in alcohol or drugs (though hopefully without the side effects).
They're colourless, odourless and apparently irresistible. Without even knowing it, we're all giving off chemical signals that either attract or repel us when it comes to the opposite sex. Even so, body odour and bad breath definitely won't cut it in the romance stakes.