LONDON (Reuters Life!) - Men only buy their own underpants when they are hoping to entice a potential partner into a relationship, according to a new survey.

Women look at underwear models in Times Square during Freshpair's National Underwear Day fashion show in New York, August 7, 2007. REUTERS/Shannon Stapleton

The poll by British retailer Debenhams showed that men normally leave the purchasing of their underwear to their mothers until about the age of 19, relatively late when compared to women, who start buying their own knickers around 13.

Between the ages of 19 and 23, men tend to buy their own underwear, up to 31 pairs a year in the belief that wearing new underpants is an essential prerequisite to a relationship.

Buying declines gradually to zero between 23 and 33, because most men are in stable relationships and leave the shopping to their partners, unless they are still on the prowl.

“Our research shows that you can tell when a man is looking for a partner by the number of new underpants they buy for themselves,” said Debenhams Head of Men’s Accessories Buying, Rob Faucherand.

“If he buys more than 31 pairs every year then he’s either still trying desperately to impress the woman in his life -- or else she’s not The One.”

However, Faucherand said that if your man seldom goes to the underwear section on his own, and instead assumes that you will choose for him, then you can be certain that your relationship is in a very stable phase.

The survey also reveals that underwear-buying among men picks up again briefly between the ages of 38 and 40, when some men are going through relationship break-ups and seeking new partners again.

The incidence of this new-found purchasing enthusiasm is short-lived however. It goes into a sharp decline and slumps to zero again at the age of 44 when men mostly find themselves in another stable relationship.

After 44, most men remain strangers to the underwear department for the rest of their lives, handing all responsibility for their underwear to women, Debenhams said.

“This is the one issue that feminism has never addressed,” Faucherand said. “It’s not who wears the pants in each household -- it’s who has to buy them that counts.”