Inoculation theory was devised by William McGuire in the early 1960s as a strategy to protect attitudes from change: to confer resistance to counter-attitudinal influences, whether such influences take the form of direct attack or sustained pressures.

Inoculation consists of two elements: threat, which raises the prospect of persuasive challenges to existing attitudes and is designed to get a person to acknowledge the vulnerability of his attitudes so that he will be motivated to strengthen them; and refutational preemption, which raises and refutes specific arguments contrary to attitudes and is designed both to provide specific content a person can use to defend her attitudes and to provide her with a model or script for defending attitudes.

Studies by McGuire in the 1960s proved, convincingly, that inoculation works. ...