I've heard of stories from female friends of mine that have gone to job interviews that take place in "non-professional environments" like restaurants, bars and clubs during off-hours.
When the women begin asking questions about the job requirements, they are dismissed and the interview glides over to the matter at hand-"what are you willing to do to get the job".
So when you see a surly cashier at a place of business, rest assured she has an attitude more than likely because she knows it's her turn to sleep with the boss that night.