The day before mixed martial artists compete in the Ultimate Fighting Championships (UFC), they pose with each other in a staged face-off. A new study has analysed photographs taken at dozens of these pre-fight encounters and found that competitors who smile are more likely to lose the match the next day (pdf via author website).
Michael Kraus and Teh-Way David Chen recruited four coders (blind to the aims of the study) to assess the presence of smiles, and smile intensity, in photographs...
