(CNN) -- Four continents, 16 cities, 192 "lost" wallets. That's the basic formula for a recent sticky fingers experiment by Reader's Digest.
Reporters from the magazine dropped wallets in parks, on sidewalks and near shopping malls in international cities from New York to Mumbai and waited to see how people would respond. Each wallet contained the equivalent of $50, a cell phone number, business cards, coupons and a family photo.
Bottom line? Nearly half -- 47% -- of the wallets were returned.
"If you find money, you can't assume it belongs to a rich man," said Ursula Smist, who returned one of the five wallets recovered in London. "It might be the last bit of money a mother has to feed her family," said Smist, who is originally from Poland. The other seven wallets dropped in London remain at large.
Of the 102 wallets subjected to the old "finders keepers" rule, one was pocketed by a male Zurich tram driver whose employer runs the city's lost and found office. In Warsaw, five of 12 wallets were returned while the other seven were pocketed by women. The magazine concluded that gender and age are unpredictable when it comes to sussing out honesty.
"The most surprising discovery for the team at Reader's Digest is that honesty is not a relative," said Raimo Moysa, editor-in-chief of Reader's Digest International Magazines. "For all the people who returned wallets, it was the only way to act in such a situation."
" 'It is something you do naturally,' said 30-year-old optician's assistant in Prague when we asked about why she returned the wallet. A 73-year-old grandmother in Rio de Janeiro expressed the same sentiment by saying simply: 'Because it is not mine,' " Moysa wrote in an e-mail response.
Check out the gallery above for a ranking of the most -- and least -- honest cities in North and South America, Asia and Europe.