Question: how has facial expression evolved :S ??

Bridget Waller answered on 21 Jun 2010:

Great question – have a look at some of the already answered questions, we have discussed this a fiar bit already. Basically, facial expressions probably originated in normal, functional reactions to things. Think about what you do if you taste something disgusting – you probably stick your tongue out, pull your lips back and do anything you can to get it out of your mouth…over evolutionary time this reaction could become ‘ritualised’ into an expression, so that others can understand how you are reacting to something. We think a similar process has probably happened for all the major expressions – happiness, sadness, anger, surprise, fear and disgust.