Inoculation theory is a theory in social psychology that explains how and why people reinforce their beliefs and attitudes to maintain them in the long term. This concept was developed in the 1950s by William J. McGuire, a social psychologist interested in the aftermath of the Korean War, where several prisoners of war opted to remain with their captors. Popular opinion suggested that they were brainwashed, which sparked an interest among researchers in finding out how such situations could be prevented in the future.
Under this theory, people who are exposed in advance to weak versions of counterarguments can start to develop defenses against them. Hearing opposition to their beliefs gives people an opportunity to formulate new arguments to support and reinforce their attitudes. Much like vaccination, inoculation theory works by exposing subjects to a mild version of a threat. When an actual threat presents itself, the body or mind is already prepared to confront it.
McGuire believed that simply exposing people to counterarguments was not enough for inoculation theory to work. They also had to have something at stake in the form of a threat that would spur them to respond to these arguments. Creating some risks in the situation would allow people to develop firmer beliefs and attitudes that would not be unseated by stronger arguments in the future. The risk may be something as simple as a warning that the subject is about to hear counterarguments and should prepare for them.
The concept of inoculation theory plays an important role in everything from advertising to rhetoric. Exposure to weak arguments to prepare people for stronger ones can help them develop more articulate and complex arguments to defend themselves. This can be seen in settings like debate classes, where students may be encouraged to argue various sides over the course of practicing for a debate. When they're actually in a competitive setting, they know what the other side may say, and they're prepared to hold their ground.
This concept even plays a role in medical practice. Researchers examine inoculation theory to learn more about how patients develop and maintain attitudes, some of which may be detrimental to their health. This information can help determine the best way to counter these attitudes. For patients who may have beneficial attitudes that are not very firmly rooted, inoculation in discussions with care providers can help patients prepare for more robust arguments in the real world so they will continue to make positive health choices.