Examining the Effects of Message Framing and Social Norms on Judgments of Earthquake Legislation
To increase earthquake preparation, it is beneficial to understand the effects of different types of information used in risk communications. This thesis adapts methods that have been used with other hazards or in hypothetical situations and applies them to increasing support for current earthquake-strengthening legislation in Wellington, New Zealand (NZ). Study 1 examined valence and numerical format framing. Expressing the number of buildings affected by the legislation as a negatively-valenced frequency was found to be most effective at increasing earthquake-related judgments¹. Study 2 examined descriptive and injunctive norms and found that a range of subject factors such as age and previous knowledge of the legislation influenced the effects of norms. Study 3 used the same manipulation and included a sample from Palmerston North, where earthquake risk perceptions are lower. This study showed several clear norm effects, with the combination of both descriptive and injunctive norms the most effective at increasing support for the earthquake legislation. All three studies showed that belief in the effectiveness of strengthening earthquake-prone buildings predicted support for the legislation and lower earthquake-risk tolerance, suggesting that this could be a key perception to target in communications. Overall, these studies suggest that certain messages are more effective at increasing support for the governmental legislation, but also that framing and social norm effects on real-world issues interact with other variables such as age and knowledge which ought to be examined further to increase the usefulness of psychological research to risk communication. ¹ The results of this study have been accepted for publication as a peer-reviewed journal article: Vinnell, L. J., McClure, J., & Milfont, T. L. (in press). Do framing messages increase support for earthquake legislation? Disaster Prevention and Management, 26(1).