Muscles to smile and frown making yourself smile exact number Snopes.com more muscles to frown Snopes.com Snopes burns more energy urban legend a page for this proverb Muscles to Smile and Frown : snopes.com the smile-frown debate under investigation Happiness Is Only Grin Deep exact number Snopes - Happiness Is Only Grin Deep Urban Legends Reference Pages Snopes has not disproven this under investigation Happiness Is Only Grin Deep Snopes.com exact number many guesses http://www.snopes.com/science/smile.asp might not be all that it's cracked up to be