When I first learned English I was extremely confused that people kept referring to grinning as smiling, given that "smiling" refers to a wider range of expressions than just that. Smiling "with teeth" doesn't come to me naturally in the situations the word is typically associated with.
Given that the "American smile" is not universal (despite the changes in most cultures over the past centuries - there was an article posted on HN a few weeks ago about how AI generated "selfies" of people from certain cultures look wrong because they wouldn't smile like that), I wonder if the association between a toothy smile and friendliness is entirely recent, evolutionarily speaking.
I also wonder if the "don't smile at dogs because bared teeth are a sign of aggression" has more to do with dogs picking up on the mismatch between the "friendly" facial expression and the emotional state of the human or if they would be equally distressed when seeing a human genuinely grinning out of sheer overwhelming joy and happiness. I find exaggerated displays of friendliness as is common in US hospitality and retail extremely unnerving personally.
Given that the "American smile" is not universal (despite the changes in most cultures over the past centuries - there was an article posted on HN a few weeks ago about how AI generated "selfies" of people from certain cultures look wrong because they wouldn't smile like that), I wonder if the association between a toothy smile and friendliness is entirely recent, evolutionarily speaking.
I also wonder if the "don't smile at dogs because bared teeth are a sign of aggression" has more to do with dogs picking up on the mismatch between the "friendly" facial expression and the emotional state of the human or if they would be equally distressed when seeing a human genuinely grinning out of sheer overwhelming joy and happiness. I find exaggerated displays of friendliness as is common in US hospitality and retail extremely unnerving personally.