The gold standard test for determining someone's honesty is seeing what that they do with a lost wallet. Do they keep it? Attempt to return it to the person who lost it? Or do they pocket the money and then dump it in a mailbox?

A researcher in Finland wanted to find out just how honest his countrymen were by posing as a tourist and dropping off a supposedly "lost" wallet with an employee at a local business and asking them to take care of it.

After the initial findings, the researchers hypothesized that if he added a larger sum of money in the billfold, fewer people would return the wallet. A poll of 279 top-performing academic economists agreed. But this time, the researchers decided to conduct the study on a larger scale.

Over two years, they staged over 17,000 wallet drops in 335 cities in 40 countries across the world and discovered that people are probably more honest than you think. The wallets were all about the same. They held a few business cards, a key, a grocery list. Some contained about $13 while others had no cash.