Comment by retsibsi

> even if it might not be a hundred percent genuine

I reckon there are a couple of ways we could define a 'genuine' smile. Most strictly, as a basically involuntary expression of emotion. More loosely, we could include voluntary smiles as long as they are a sincere signal of goodwill. I don't really want to be smiled at by people who hate me, but I think there's plenty to be said for cultural norms in favour of 'genuine' smiles under the looser definition.