People return lost wallets that contain baby pictures
If you lose your wallet and it has a picture of a baby in it, there’s an incredibly high chance you’ll get it back:
When faced with the photograph of the baby people were far more likely to send the wallet back, the study found. In fact, only one in ten were hard-hearted enough not to do so. With no picture to tug at the emotions, just one in seven were sent back.
Any baby picture will do of course, so this will work for people with no kids, too.