There are two main aspects that bond science and dating, the smell and the body shape.

Smell

Desire is based on someone’s genes being a superior match for yours, say scientists. You’re observing someone and figuring out whether you want your children to carry that person’s genes. So if you fancy someone, you’ve decided without realising that their genes will mix with yours to generate strong kids.

But how does this happen? We factually smell out our date’s genetic fitness. Scientists have known for some time that pheromones can set off great sexual responses in animals but until recently they’d assumed that humans had lost that capability.

Then in 1985, researchers found pheromone sensors in human nostrils, which attach directly to the part of the brain in charge of emotions, such as helpless lust for the bloke sitting opposite you in the pub.

Scientists then decided to investigate pheromones and found that women preferred the pheromones of men with different immune systems to their own.

Body Shape

Separately from pheromones, body shape is the other main way we use to work out whether a bloke is attractive or not.

Shape and symmetry theoretically tell our subconscious minds all sorts of things about fitness and hereditary health. So if the features on your face or elsewhere on your body aren’t constant, then they are a clue to potential genetic problems.

It also seems that men are very worried about looking for reasonable features, while women are preoccupied by pheromones. A recent study at the University of New Mexico found that male college students preferred symmetrical female faces and discovered that symmetrically-featured women had more sexual partners and were sexually active at a younger age.

Men have also been shown to prefer women with a waist-to-hip ratio of 0.7. You can work this out by dividing your waist measurement by the inches around your hips.

This figure allegedly relates to physical fitness and fertility and doesn’t really matter what you weight, which is reassuring to those of us trying to drop a dress size.