Men don't have a great reputation when it comes to chipping in with the housework. Many a man's idea of helping out with the cleaning is selflessly to decamp to watch the football on the kitchen telly while his wife vacuums the sitting room. To many men, cleaning can feel a bit futile; like raking the leaves off the lawn in the middle of an autumnal windstorm. Bleach? Yes, men know it exists, but aren't certain what it is actually for: they believe that most household emergencies can be fixed with WD-40. Yet men also feel cruelly misunderstood. A man doesn't clear out the fridge not because he is lazy, but because he takes seriously his protective hunter-gatherer role: he believes the day will come when - with the larder bare - the family will be grateful he never threw out the leftovers of the Chinese takeaway they bought to celebrate the Apollo 11 Moon landing.

It also irks men that if a woman leaves a sweater on the back of a chair, her partner won't nag or even mention it, but if he uses the bedroom floor like an alfresco laundry basket, he's a slob.

But now psychologists have pinpointed a tool far more efficacious than nagging to cajole lazy men into pulling their weight with the mop.

Alongside research showing that many men are shouldering more of the housework (though still not an equal share), the American Council on Contemporary Families has found that equitable sharing of housework can lead to happier marriage and more frequent sex. That's right! It turns out that cleanliness is not next to Godliness. It's next to sexiness. Women get hot for a man who dusts. Either that or it has something to do with gene-pool selection, and women are calculating that a man who (unlike most of his gender) can enter a grimy bathroom and actually see that it is hosting a colony of bacteria big enough to qualify to hold its own US election caucus may have optical genes worth passing on to her offspring.

So, you don't possess George Clooney's twinkly smile? Or Brad Pitt's chiselled pecs? You don't need them. A pair of Marigolds will do.