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  • March 20, 2019
  • El-Toukhy, Sherine
    • Affiliation: Hussman School of Journalism and Media
  • Communication initiatives frequently are used to inform people about various risks in an attempt to improve their decision making and behavior. People, however, do not readily accept personal risk information, often underestimating their susceptibility to and the severity of the risks. This dissertation draws on psychological theory and research to explain why people underestimate their risks. Three experiments were designed to test whether people have an automatic tendency to underestimate self-relevant risks - the default option that occurs without conscious awareness of underestimation of health risks as a bias and of self-schema activation as a source of this bias and is likely to occur when people are mentally taxed. Rationale for the theoretical propositions advanced here is derived from research documenting that health risk information is (a) processed as self-relevant, (b) inconsistent with the positivity bias and self-threatening, and that (c) the activation of the self-schema is automatic. Experiment 1 tested the hypothesis that people underestimate their likelihood of experiencing negative health conditions and overestimate their likelihood of experiencing positive ones. Experiment 2 examined whether underestimation of health risks is an efficient process, one that occurs when people are mentally taxed. Finally, Experiment 3 tested the effects of health risk controllability and psychological reactance on health risk perceptions. All three experiments relied on priming to activate the self-schema and measured the effects of this activation on reaction time, an implicit measure of risk perceptions. Several individual difference variables (e.g., self efficacy) and health risk characteristics (e.g., prevalence) that influence risk perceptions were controlled for. Results show that people automatically underestimate their health risks, that is, without awareness, intention, or effort. The studies provided conclusive evidence of (a) underestimation of susceptibility to negative health conditions and overestimation of susceptibility to positive ones and (b) efficiency of underestimation of health risks. Results regarding self-schema activation as a source of underestimation of risks were not as conclusive. Individual difference variables did not affect implicit measures of risk perceptions. Health risk characteristics, on the other hand, influenced risk perceptions. The experiments showed an inverted relationship between susceptibility and severity dimensions of health risk perceptions.
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Rights statement
  • In Copyright
  • Gibson, Rhonda
  • Brown, Jane D.
  • Kalyanaraman, Sriram
  • Rimal, Rajiv
  • Chartrand, Tanya
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill Graduate School
Graduation year
  • 2012
  • This item is restricted from public view for 1 year after publication.

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