“Convincing smiles are to some extent a signal of the intrinsic character of trustees: less honest individuals find smiling convincingly more difficult. They are also informative about the greater amounts that trustees playing for higher stakes have available to share: it is harder to smile convincingly if you have less to offer.”

— Centorrino, Djemai, Hopfensitz, Milinski & Seabright, 2011 [PDF, via]

Photo:  My most authentic smile.  Don’t you find me trustworthy?