Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)

Graduate Group


First Advisor

Joseph N. Cappella


According to the doctrine of informed consent, research participants have a right to voluntarily decide whether to enroll in a study and to do so with an adequate understanding of what participation entails (Beauchamp & Childress, 2009). Mirroring these rights, investigators have a moral obligation to give people the facts that are most critical to their choices (Fischhoff, 2011). Yet, theory-based analytical tools for determining which information is likely to have the largest impact on participation decisions are underdeveloped. Lacking a basis to prioritize elements of disclosure for distinct audiences, the length and complexity of consent documents has increased over time. Ironically, these improvements may have hindered comprehension and people's access to the information they need to make informed choices.

According to the reasoned action model (Fishbein & Ajzen, 2010), decisions to participate in genomics research--like any other behavior--are driven by a limited number of factors. In this dissertation, consequences of participating that readily came to mind for respondents were expected to have a larger impact on attitudes and intentions to participate in genomics research than were nonsalient consequences. Moreover, customized messages designed to target salient versus nonsalient beliefs were expected to have larger effects on attitude and intention. Based on media priming theory (e.g., Price & Tewksbury, 1997), plausible downstream effects on belief salience resulting from message exposure were also explored, as was the conditional effect of salience on belief change (Jaccard, 1981).

An open-ended belief elicitation in Study 1 revealed audience segments with different motivations for participating in a genetic biobank. Contributing to the greater good was especially salient for some respondents, while receiving personal test results was salient for others. In Study 2, an experimental design was used to test the conditional effects of segment-targeted messages on belief strength, attitudes and intentions toward participating in a fictional genomic research project. Both studies suggested that salient behavior-related beliefs had a larger influence on people's participation decisions. Results from Study 2 further indicated that salient beliefs might also be more difficult to change. Theoretical and practical implications for fostering informed consent in large-scale genomic research are discussed.

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