Researchers found we spend old or filthy bank-notes more freely than freshly-minted ones.Professors Fabrizio Di Muro and Theodore Noseworthy said dirty and clean bank-notes evoke feelings of disgust and pride in equal measure.

They said: "The physical appearance of money can alter spending behaviour. Consumers tend to infer that worn bills are used and contaminated, whereas crisp bills give them a sense of pride in owning bills that can be spent around others."

Prof Di Muro, of Winnipeg University, and Prof Noseworthy, of Guelph University in Ontario, said we don't like the idea of touching something countless other people have also handled.This is magnified when a bank-note is dirty, worn or crumpled because we can see evidence this cash has passed through a lot of hands before getting to ours, they said.

The researchers added: "Consumers may value a crisp banknote more than a worn bank-note because they believe the latter is disgusting and thus want to be rid of it."In several studies consumers were given either crisp or worn bills and asked to complete a series of tasks related to shopping.

They tended to spend more with worn bills than with crisp bills. They were also more likely to break a worn larger bill than pay the exact amount in crisp lower denominations.However, when consumers thought they were being socially monitored, they tended to spend crisp bills more than worn bills.

To read the complete article, see:Filthy banknotes get spent more quickly than crisp notes(www.telegraph.co.uk/finance/personalfinance/9677664/Filthy-banknotes
-get-spent-more-quickly-than-crisp-notes.html)