You can't put a price on a smile, so the old saying goes. But researchers at Bangor University have done just that, calculating that a smile is worth exactly one third of a penny – and that it's a form of "social currency" that people will pay for.
They found that people preferred to play against opponents with genuine smiles – even when that meant they were less likely to win. "Our participants, all university students, are usually highly motivated to earn money," said Danielle Shore, lead author of the research. "The fact that they chose opponents who were less likely to pay out was a big surprise."
So what are the implications of these findings? That smiling pays. "Genuine smiles might help people see eye-to-eye during interactions," says Shore. "People who often make genuine smiles may have an easier time convincing others to adopt their goals."