Often times when an employee, such as a receptionist of a hotel, smiles back to the customer, he or she immediately observes a thick layer of bitterness behind the smile (called emotional labor). In other words she is forced to smile even though she doesn’t fell like it.
In psychology, the fake or forced smile (the one in which specific muscles of the face are "activated", around the mouth, and not the eyes – the zygomatic major and not the orbicularis oculi) has a specific name.
It is called the "Pan Am smile", or "Botox smile", derived from the "fake" smile of the flight attendants of the Pan Am airline, who were trained to always smile, no matter the circumstance, or what a customer does
Their smile indicated politeness, however it was completely forced, standardized and insincere.
Although Pan Am is long dead, its smile is still around us all the time, everywhere we go…