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Show 282 Rebecca Stoffel LAY PERCEPTIONS OF GENETIC DETERMINISM: AN EXPERIMENTAL STUDY OF THE IMPACT OF GENETIC PENETRANCE ON PERCEPTIONS OF DISEASE RISK AND PREVENTABILITY Rebecca Stoffel (Lisa G. Aspinwall) Department of Psychology University of Utah honors college spring 2012 Scientific understanding of the genetic contributions to chronic disease is growing, creating a corresponding need to understand how patients perceive personal risk and prevention options. Eighty-four university students participated in an experiment about their beliefs regarding dis-ease risk and preventability. Participants evaluated three scenarios of hypothetical individuals, each with a different stated genetic risk (penetrance of 20%, 50% and 80%) for heart disease or cancer, and information regarding their healthy, average, or unhealthy diet and exercise habits. We predicted that the influence of un/healthy behaviors would vary across penetrance levels, such that that the effect of preventive factors (such as healthy diet and exercise) may be more or less influential depending on level of penetrance and particularly that the influence of health behaviors would be greatest for lower penetrance levels. As expected, lifetime risk ratings increased significantly across Penetrance levels (20%, mean=26.90%; 50%, mean=51.67%; and 80%, mean=75.40%, F(2,156)=444.94, p<.0001); however, health behaviors also had a significant main effect on perceived lifetime risk, such that healthy behaviors resulted in the lowest perceived lifetime risk (M= 41.131%), and unhealthy behaviors increased perceived lifetime risk above each given penetrance level (M=61.119%, F(2,78) =20.906, p<.0001). For ratings of disease likelihood compared to the average person, health behaviors reduced the perceived likelihood of disease more at low levels of penetrance (20%) than at higher levels (50% and 80%). In contrast, participants rated the practice of unhealthful behaviors to be especially damaging to targets at high genetic risk. Heart disease was rated as more personally controllable than cancer, but both diseases were rated as less controllable (but still near the scale midpoint) as penetrance increased. Implications for communicating genetic risk and health behavior recommendations to members of high-risk families are discussed. Lisa G. Aspinwall |