The Impact of Threat Appeals on Fear Arousal and Driver Behavior: A Meta-Analysis of Experimental Research 1990–2011 Rachel N. Carey 1 , Daragh T. McDermott 2 , Kiran M. Sarma 1 * 1 School of Psychology, National University of Ireland, Galway, Galway, Ireland, 2 Department of Psychology, Anglia Ruskin University, Cambridge, United Kingdom Abstract The existing empirical research exploring the impact of threat appeals on driver behavior has reported inconsistent findings. In an effort to provide an up-to-date synthesis of the experimental findings, meta-analytic techniques were employed to examine the impact of threat-based messages on fear arousal and on lab-based indices of driving behavior. Experimental studies (k = 13, N = 3044), conducted between 1990 and 2011, were included in the analyses. The aims of the current analysis were (a) to examine whether or not the experimental manipulations had a significant impact on evoked fear, (b) to examine the impact of threat appeals on three distinct indices of driving, and (c) to identify moderators and mediators of the relationship between fear and driving outcomes. Large effects emerged for the level of fear evoked, with experimental groups reporting increased fear arousal in comparison to control groups (r = .64, n = 619, p,.01). The effect of threat appeals on driving outcomes, however, was not significant (r = .03, p = .17). This analysis of the experimental literature indicates that threat appeals can lead to increased fear arousal, but do not appear to have the desired impact on driving behavior. We discuss these findings in the context of threat-based road safety campaigns and future directions for experimental research in this area. Citation: Carey RN, McDermott DT, Sarma KM (2013) The Impact of Threat Appeals on Fear Arousal and Driver Behavior: A Meta-Analysis of Experimental Research 1990–2011. PLoS ONE 8(5): e62821. doi:10.1371/journal.pone.0062821 Editor: Aldo Rustichini, University of Minnesota, United States of America Received December 19, 2012; Accepted March 6, 2013; Published May 17, 2013 Copyright: ß 2013 Carey et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This research is supported by a bursary from the Road Safety Authority of Ireland. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: kiran.sarma@nuigalway.ie Introduction Risky and reckless driving behavior is a central concern for law enforcement and road safety agencies world-wide, and is linked to increased road traffic collisions (RTCs), injuries and fatalities. The World Health Organisation has estimated that, by 2020, RTCs will be the third largest cause of death worldwide. It is unsurprising, then, that road safety organizations have gone to considerable effort and expense to wage mass-media campaigns aimed at changing driver practice. One approach that is often employed in these campaigns is the use of threat-based advertising, or ‘threat appeals’. Threat appeals have been widely utilized in road safety advertising campaigns in an attempt to discourage risky driving, and typically present graphic representations of the death and injury that may occur as a result of a RTC. Despite their prevalence, threat appeals have provoked controversy for both ethical and practical reasons, and their effectiveness as a form of persuasive communication has been questioned [1]. This is partly due to inconsistent findings in the empirical research. Specifically, while some papers argue that threat appeals can be highly effective, provided a number of conditions are met [e.g. 2], findings from other studies suggest that they can lead to maladaptive responses, and may even provoke an increase in the risky behavior [e.g. 3,4]. These inconsistencies in the literature have made it difficult to authoritatively advise road safety practitioners as to ‘what works’ when designing threat appeals, as well as whether or not such appeals should feature prominently in road safety communica- tions. Meta-analyses of the research investigating the impact of threat appeals on driver behavior can help clarify the utility of this approach. The central objective of this paper is to present the first meta-analysis of the experimental research that has directly tested the impact of threat appeals on indices of driving. Existing evidence There are two important points about the existing evidence- base that suggest a meta-analysis of this nature is warranted. First, while there have been a number of high-quality meta-analyses published relevant to driver behavior, these analyses are of limited value in informing our understanding of road safety threat appeals. This is because no meta-analysis has specifically examined the impact of threat appeals on driving. Instead, these studies have tended to combine multiple risky behaviors (e.g. non-condom use and smoking [5]) in their analyses, or have combined different types of road safety campaigns (e.g. threat-based and education- based [6]) to ascertain if mass-media campaigns, in general, are effective. Thus, the results of this body of empirical literature may lack predictive validity in informing our predictions as to the impact of threat appeals on driving behavior. Second, the experimental literature in the area has reported inconsistent findings, reflecting variations in the robustness of the designs PLOS ONE | www.plosone.org 1 May 2013 | Volume 8 | Issue 5 | e62821