Originally Posted by SilentKnight

Stereotypes.

If it walks like a duck, quacks like a duck...

Another way of saying stereotypes is "educated guess based on prior experience".

They say insanity is defined as doing the same thing over and over and expecting a different result. If a large percentage of your customers don't tip and do nothing but complain about service to get a free meal - would it be sane to expect the results to just arbitrarily change? No, instead you'd rely on your best educated guess based on prior experience.

You'd call it racial profiling because that's what generates the most sympathy and looks good in headlines.