Certainty as an amplifier of message matching

Access to thesis permanently restricted to Ball State community onlyLiberals and conservatives have different moral profiles underlying their ideologies, which leads to divergent intuitions and attitudes (Graham, Haidt, & Nosek, 2009). Research has focused on how tailoring arguments to liberal or conservative moral values can evoke attitude change when resistance is the default. Across two studies, I tested two competing hypotheses regarding the role of ideological certainty as a moderator of the effectiveness of moral message tailoring. In line with prior work suggesting that certainty magnifies the effects of an attitude’s basis and leads to increased persuasion (Clarkson, Tormala, & Rucker, 2011), I hypothesized that those highly certain in their ideology will be the most likely to change their attitudes when the message appeals to their morals. However, it was also possible that high certainty may result in increased resistance to persuasion (Clarkson et al., 2011), even when the message appeals to consistent moral values. I found that at low levels of certainty, persuasive messages in general increased conservative participants’ endorsement of pro-environmental stances, while highly certain conservatives were more persuaded by messages framed in moral language counter to their own moral values. These findings shed new insight into the ways political ideology and certainty interact to influence how people perceive moral persuasive messages and serves as an impetus for further research.Department of Psychological ScienceThesis (M.A.