The smile, lest it be laughed off, has its origins in the 'fear grin' of apes who use barely clenched teeth to 'tell' predators they are harmless, or to submit to more dominant group members. 30 million years of evolution and practice later, the Big Ape - us, humans - turned it into an even more 'friendly' smile, adding the laugh, smirk, grin, beam and guffaw in the face's non-verbal arsenal. Now, do you get why getting it right beyond sending a 'smiley' emoji is so important?