Efficacy of inoculation strategies in promoting resistance to political attack messages: Source credibility perspective.

Abstract

Taken together, the results of this dissertation indicate that inoculation is an effective resistance option for candidates in deflecting the influence of political attack messages delivered in both political advertising and televised candidate debates.

Finally, the research investigated the potential of inoculation in another influential campaign communication venue, televised political debates. A separate set of data for the debate study was gathered and analyzed. The results also confirmed the efficacy of inoculation in that positive attitudes towards candidates were significantly greater for the inoculation group as opposed to the no-inoculation group. Importantly, this finding is a new addition to inoculation research in political campaign communication. The debate study also explored the potential of inoculation to strengthen receivers' normative values, mitigating against the destructive impact of debate messages on the democratic process.

As one of the most pronounced changes in American political campaigns, the growth of attack messages has received extensive attention from scholars. Still, political attack messages remain one of the most virulent of election phenomena. Inoculation strategy has convincingly proved itself more viable than other options. This experimental study investigated the potential of inoculation strategy in conferring resistance to candidates' attack messages during the 2002 Oklahoma state election. The results of the current study clearly confirm that inoculation is effective in deflecting the impact of attack messages on receivers' attitudes toward candidates. In addition, the results indicate that inoculation strategy promotes behavioral resistance, reducing the likelihood of voters' participatory slippage from attack messages. Also, this investigation revisited source credibility, one of the most studied concepts in persuasion. With its growing importance in media politics (Iyengar & Valention, 2002; Lupia, 2000), source credibility was explored as to its role and impact in inoculation. The results indicated that a candidate's inoculation strategy can be more effective when receivers perceive his/her credibility more favorably. When treated by high candidate credibility, inoculated receivers were significantly less affected by opponent's attack messages than those treated by low credibility. The results revealed source credibility can mediate inoculation, enhancing or reducing the inoculation effect depending on how viewers evaluate candidates' credibility, particularly expertise and trustworthiness.