“McGuire’s (Papageorgis & McGuire, 1961, 1961a; 1961b) original conceptualization
of inoculation theory proposed that individuals can be inoculated against counter-
attitudinal attacks in a manner similar to immunization against viral attacks.
Just as preemptive immunization shots protect people from future exposure to viruses,
McGuire posited that preemptive messages could protect attitudes from subsequent
exposure to counterattitudinal persuasive messages. Inoculation treatments contain
two essential message features: threat and refutational preemption (Compton & Pfau,
2005; Szabo & Pfau, 2002). Threat is the motivational component of an inoculation.
It forewarns of a persuasive attack, highlighting the vulnerability of an individual’s
current attitudes, and thereby motivates resistance. The refutational preemption
component contains specific content that can be used to bolster attitudes against
an impending attack (Pfau et al., 1997). The purpose of the refutational component
is twofold: It provides individuals with arguments or evidence that can be used to
counter persuasive attacks, and it also allows individuals to practice defending their
beliefs through counterarguing (Compton & Pfau, 2005; Insko, 1967; Wyer, 1974).
Research reveals inoculation to be an effective strategy for conferring resistance
to persuasion. … Conspiracy theories present an interesting challenge for inoculation scholars
because they defy the rational, logical, and reasoned approach exemplified by
inoculation interventions. Conspiratorial arguments often employ circular reasoning,
repetition of unproven premises, nonfalsifiable premises, and a host of other logical
flaws (Miller, 2002). Persuasion is not a purely rational process, however, and dual-
process theories (e.g., Petty & Cacioppo, 1986) apply the metaphor of two separate
routes to persuasion: A central route, based on careful processing of the evidence;
and a peripheral route, based on some mental shortcut instead of careful evaluation
of arguments and evidence. These theories propose that both motivation and ability
to process persuasive messages are necessary for central route processing to occur.
Watching a film is a more passive process than reading, which should reduce the
ability to counterargue or process many of the empirical claims presented (Compton
& Pfau, 2005).”
This investigation examined the boundaries of inoculation theory by examining how inoculation can be applied to conspiracy theory propaganda as well as inoculation itself (called metainoculation). A 3-phase experiment with 312 participants compared 3 main groups: no-treatment control, inoculation, and metainoculation. Research questions explored how inoculation and metainoculation effects differ based on the argument structure of inoculation messages (fact- vs. logic-based). The attack message was a 40-minute chapter from the 9/11 Truth conspiracy theory film, Loose Change: Final Cut. The results indicated that both the inoculation treatments induced more resistance than the control message, with the fact-based treatment being the most effective. The results also revealed that metainoculation treatments reduced the efficacy of the inoculation treatments.