Descriptive norms can be seen operating when street performers, cocktail lounge pianists, coat-check attendants, baristas, and others who work for tips “seed” their tip containers with bills in the amounts they hope their customers will contribute. The idea is that if a pianist’s tip jar already holds a few five-dollar bills, and maybe even a ten, listeners are led to assume that these are normal tip amounts and might thus be more likely to contribute similar amounts themselves.

The human tendency to obey the orders of legitimate authority figures has been exploited by pranksters who have influenced unsuspecting people to engage in outrageous and potentially dangerous or harmful behavior. For example, in April 2016, employees of California and Oklahoma fast-food restaurants broke out all their stores’ windows after callers claiming to be fire department officials ordered them to ventilate supposedly deadly levels of carbon monoxide. Orders from a caller posing as a Boston police detective led four restaurant managers there to strip-search their employees for evidence of criminal activity. In other cases, residents of a special needs school were given unnecessary electric shock treatments on the telephoned orders of a hoaxer, and hospital nurses obeyed medical treatment orders given by a teenager who claimed to be a doctor. A summary of such cases, and the details of one in 2004 that led to a criminal trial for the caller are available in this news story. A much more elaborate description of this hoax, its perpetrator, and its horrific impact on some of its targets is presented in a three-episode series on Netflix.

A short video found here illustrates the power of words to influence the behavior of others, in this case, to create empathy and generosity.