Answer: SELF FULFILLING PROPHECY
Explanation:
Self fulfilling prophecy is the phenomenon of an individual anticipating something; and the anticipation later surfaces and comes to fruition just for the fact that the individual believes that his expectation will manifest. Oftentimes, their behaviours go in tandem with the beliefs to be fulfilled.
When it comes to self- fulfilling prophecy, a person's expectations or perception concerning another individual or something later conforms with the other individual or thing behaving in manners that agree with the initial perceptions. In self- fulfilling prophecy, initial false anticipation later results to its own confirmation.
It is important to note that people design and manufacture repercussions or results with respect to other people or entities due to their prior knowledge or idea or experience concerning a particular subject or issue
Now, with respect to the waitress that already concluded in her mind or assumed that a group of poorly dressed customers will be ungenerous with tipping; This is a clear-cut case of self fulfilling prophecy because after her assumption that those customers will be ungenerous tippers which now made her to offer them very little attention, her prediction became reality when she got a small tip in the end just as she anticipated.