A cashier at the store assumes that because his next customer is elderly, she will take a long time to pay. The cashier is using his stereotypes about the elderly and not taking the time or energy to carefully consider each customer in his line as an individual. His use of stereotypes best exemplifies Allport's idea of .the contact hypothesisthe law of least prejudice

the law of least effort

Explanation:

Effort is commonly defined as the attempt, effortary, zeal, ability to carry out a task, exert power etc. It is determined by Incubating or holding several things, ideas, task in mind usually at once, each having different/separate actions, or that need to be combined according to a rule.

The Law of Least Effort simply shows that whenseveral ways of achieving the same goal is identified or open, individuals tends chose or eventually moves to the least demanding task(course of action). In this, laziness is therefore built deep into the human nature.

the telephone is the answer