The press is replete with guidelines regarding preventive behaviors, such as exercise, vitamins, or food choices. Such guidelines may have unintended negative effects on consumers if later reversed. We report a study examining the effect of evolving health guidelines on consumers' initial response and critical "spillover" outcomes-consumers' faith in health guidelines in general and consumers' intention to perform related health behaviors not part of the guideline. We find that a guideline change from taking an action to inaction increases negative spillovers, consistent with omission bias and betrayal aversion. A follow-up experiment with policy implications for mitigating this undesired backlash will also be reported. [to cite]: Christine Moorman, Mary Frances Luce, and James R. Bettman (2008) SESSION OVERVIEW From news reports on the radio, television, internet, and magazines to focused health campaigns targeting susceptible groups, consumers are bombarded with health messages produced by ongoing medical studies, government agencies, for-profit health and insurance firms, and community and public health non-profits. A Google search of "health" produced 939,000,000 hits, "nutrition" produced 148,000,000 hits, and the specific phrases "health news" (6,140,000) and "health communications (651,000) produced a sizable number of hits. These numbers suggest that health messages are a fundamental part of the mosaic of communications consumers encounter every day and constitute a key component of campaigns designed to reduce morbidity and mortality. These numbers and other indicators also point to trends involving increased consumer responsibility for their own care and shifts in medical culture from paternalism towards informed consent. Despite these positive forces, most health communications produce low compliance and rather dismal results. Most health communications are undertaken to alter consumer action. Conventional wisdom is that if health communications are sufficiently informative and persuasive (increasing knowledge, efficacy, or motivation), then appropriate action will follow. This session's papers challenge this wisdom. The first two papers sharpen our understanding of how to use health communication to alter consumer action; the second two papers point to important downstream problems occurring after consumers are motivated to act. Anand Keller and Lehmann report a meta-analysis of 85 health communications studies. They find that message factors, not individual differences or context, dominate explanations of effectiveness. They also show important differences in effects on attitudes toward health behaviors and intentions to change behaviors that may critically influence whether we judge a campaign to be successful or not. Their research underscores the importance of conceptualizing and measuring consumer action (rather than simply consumer attitudes) as a key health communication goal. The second paper, by Anand Keller, extends this theme of the focal nature of consumer action by using mental simulation of healthpromoting actions as a focus of intervention. She challenges the current idea that hope and confidence produce more preventive health behaviors and suggests that increasing consumer anxiety is more effective by producing higher need for action taken to regain control. The third and fourth papers illustrate complementary difficulties in using health communication to alter action. Moorman, Luce, and Bettman argue that consumers may not always benefit from the evolving nature of health guidelines. As medical science sheds more light on the effect of healthy choices or treatment options, communications that initially advocate positive actions (e.g., take a vitamin supplement) but later reverse these suggestions may ultimately degrade consumers' view of health guidelines and decrease their likelihood of performing related health behaviors. Tanner shows that teens may provide inaccurate reports of actions related to risky behaviors when participating in the evaluation of community-based health programs. Inaccuracy is particularly problematic when teens are made aware of desirable health behaviors, when they believe their anonymity may not be protected, or when minimizing, not exaggerating, certain behaviors. Looking across papers, we see several emerging questions regarding the promise and pitfalls of using health communications to alter health behavior: (1) Do health communications work in the short and long-term? Unsurprisingly, numerous studies have assessed the impact of different communication strategies (e.g. level of fear arousal or framing) on subjects' attitudes toward and intentions with respect to various health behaviors. However, the large number of studies and the variability of the findings suggest a quantitative synthesis of this area would be beneficial. The purpose of this paper, therefore, is to assess the current state of knowledge in the field via metaanalysis. In particular, we wanted to identify the context, message and individual factors that increased attitudes and intentions to comply with the recommended health behaviors. For that purpose, we conducted a meta-analysis on data reported in 85 published and unpublished articles in the consumer research, psychology, health, and communications literatures
