An old wives? tale advises young men in search of love to carry a handkerchief tucked in their armpits at dances: once the dance is over, they should remove the hanky and fan their partners with it. The scent will act as an aphrodisiac!

The story came to mind when I read that this year?s Nobel prize for medicine had been awarded to US researchers Richard Axel and Linda B. Buck for their work on the little-understood sense of smell.

Part of Axel and Buck?s research concerns human pheromones ? chemical substances exuded as ?airborne messages? between members, especially of the opposite gender, of the same species. They?ve managed to map the receptors in the brain that track the effect of specific pheromones.

For years, the perfume industry has attempted to create a scent that puts the magic of pheromones to use: imagine a perfume that would make you irresistible to the opposite sex. It?s the Holy Grail of scent ? and so far, attempts to create the ultimate Pheromone Parfum have flopped badly.

Axel and Buck?s research suggests this is because humans react to pheromones and their close cousin, chemosignals, in very individual ways. Chemosignals are odours secreted by humans that determine such things as your choice of partners. But they are easily masked by background smells, which is why we don?t walk around in conscious awareness of future or potential mates.

Or do we? A study carried out at the University of Chicago determined that women have strong inherited genetic preferences in the choice of mates ? which they demonstrate through the power of the sniff. Women chose partners who were genetically neither terribly similar to them nor terribly dissimilar, but who fell in between ? they could actually ?smell? genetic difference. The key element when it came to choosing between different male odours turned out to be driven by genes inherited from their fathers, not their mothers.

So when we choose partners, we?re choosing men whose scents are different from our own genetically, but not completely different: and who we choose will depend on the genetic inheritance our dads have passed down!

This explains why a pheromone perfume wouldn?t work unless it was individually tailored: with such a wide variation in preferences, no one perfume could be all things to everyone.

A more recent study by the Chicago team explored sexual desire and came up with surprising findings. Breastfeeding women exude a chemosignal that heightens sexual desire in other women around them who aren?t pregnant or nursing themselves ? possibly nature?s way of encouraging women to have more children in times of relative plenty, researchers hypothesise.

It?s as plain as the nose on your face: women?s choice of partners or their levels of desire are regulated by the humblest of the organs of sense. Which begs the question: how do people with a damaged sense of smell or with a long-running cold fare with their relationships? Perhaps the new Nobel laureates have some answers!