3 . Imagine that you found a wallet in the street containing a stranger 's contact details but no cash. Would you go out of your way to return it to its owner? Now imagine that the same wallet contained a few banknotes. Would that change your response? Alain Cohn of the University of Michigan and his colleagues have taken such behavioral economics around the world.

In different countries Dr. Cohn's research assistants entered public buildings like banks, museums and police stations. They handed in a fake wallet to an employee in the reception area, saying they had found it on the street outside, before making a hurried exit. Each wallet was a see-through plastic card case containing three identical business cards with a unique email address and a fake native's name, a shopping list and a key. Most importantly, some wallets also included $13.45, while some had no cash. Then, the team simply waited to see who would email the “owner” about returning the wallet.

In 38 of the 40 countries, the wallets with money in them were returned more often than those without: 51% compared with 40% for the cashless. While rates of honesty varied greatly between different countries, the difference within individual countries between the two return rates was quite stable around 11 percentage points. In addition, wallets containing a larger sum of money ($94.15) were even more likely (by about another ten percentage points) to be returned than those with less, although the “big money” experiment was done in only three countries.

With greater temptation (诱惑), then, comes greater honesty - at least when it comes to lost wallets and small cash. Interestingly, though, when Dr. Cohn and his team surveyed a sample of 299 volunteers, most of them predicted that the more money there was in a wallet, the more likely it was that it would be kept.

A certain doubt about the motivation of others is probably good for survival, so the response of the general population may be understandable. But is the warm inner satisfaction coming from “doing the right thing” also a powerful reason? As this study shows, such thought is real and universal

4 . Whether you're looking for antiques, food, collectors' items or just random junk, our rich heritage has produced some of the finest markets in the world. Here are 3 of them.

Traders have long sold their goods in the shadow of the city’s spectacular castle, which dates back to 1130—－and it’s a tradition that shows no sign of abating. Edinburgh Farmers’ Market takes place on Castle Terrace every Saturday and attracts a huge crowd with its locally sourced goods. The market is now in its 15th year and champions the very best in Scottish produce, from knitwear to organic water buffalo and lobster.

Looking for an old-style prosthetic leg, a ventriloquist’s dummy, or even a suit of armour? The chances are you will find what you are after—and plenty of other random stuff—at one of the hundreds of stalls here. A market and two huge car-boot sales are held throughout the week all year round, come rain or shine.The market has been running for 25 years and is a well-known treasure trove for antiques experts looking for a bargain.

Follow your nose along May Street in Belfast and the smells of delicious home-made food from across the globe will land you in St George’s Market. With three different weekly markets accompanied by fresh food and live music, St George’s was once voted the best in the UK. When Belfast became an important port in the 17th century, the range of goods grew and trading thrived.