Psychology ETDs

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This study attempts to experimentally manipulate core constructs of the Health Belief Model (HBM) and the Theory of Planned Behavior (TPB) in order to increase condom use behavior. A direct comparison of the two models to determine the theory that best explains condom use behavior change will also be attempted. University of New Mexico psychology students (N = 280) completed measures on perceived susceptibility, severity, benefits, barriers, condom use self-efficacy, attitudes toward condoms, subjective norms, and perceived behavioral control. Next, they completed one of three randomly assigned computer-based interventions. 218 (77.8%) completed a behavioral assessment one month later. The TPB was best at explaining risky sexual behavior at baseline; it explained 30.6% of the variance while the HBM only explained 1.5% of the variance. The interventions were able to manipulate every predictor but perceived barriers. Mediational analyses of the HBM revealed that intervention type had an effect on perceived susceptibility, benefits, barriers, and condom use self-efficacy, but none of these mediators predicted risky sexual behavior at follow-up. TPB mediators attitudes toward condom use and subjective norms were influenced by intervention type. Subjective norms and perceived behavioral control predicted intentions, but intentions did not predict behavior at follow-up. This study supports the assertion that theory-based interventions are more effective at changing proposed mediators of behavior; however, it was not successful at eliciting behavior change. In sum, current behavior theories should be rigorously examined and modified if need be to create more comprehensive theories of behavior change.

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First Advisor

Bryan, Angela

First Committee Member (Chair)

Smith, Bruce

Second Committee Member

Yeater, Elizabeth




Condom use--Psychological aspects, Health Belief Model, Attitude (Psychology), Operant behavior, Motivational interviewing.

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