Term of Award

Summer 2017

Degree Name

Master of Science in Experimental Psychology (M.S.)

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


Department of Psychology

Committee Chair

Lawrence Locker

Committee Member 1

Karen Naufel

Committee Member 2

Rebecca Ryan


Tornado activity annually results in many deaths throughout the U.S. As a result, the emergency alert system (including tornado warnings) has made considerable advancements throughout the past few decades. However, continued improvements could be made to warning content that aid to facilitate adaptive decision-making by increasing individuals’ motivation to respond. One method that could increase adaptive responses to warnings is by including the modality of descriptive social information within the warning. Research suggests that normative social influence acts as a powerful motivator for individuals to conform toward the witnessed or perceived behaviors of others. The current study examined the impact of descriptive social normative information in the context of tornado warnings. National Weather Service tornado warnings were modified to display social information concerning the percent of people taking shelter in a localized area. We examined the effect of social influence and tornado severity on perceptions of (1) susceptibility to the threat, (2) response-efficacy, and (3) self-efficacy, as well as comprehension of the auditory and visual variables of the warning content. Results confirmed previous findings for perceived susceptibility (i.e., F4 category tornadoes were perceived as more severe the F2 category) and comprehension of warning information (i.e., comprehension was significantly worse for the F4 category compared to the F2 category warnings). A boomerang effect was observed for the effect social influence within the F2 category condition with regard to the response-efficacy outcome measure. Further results and implications are discussed.

Research Data and Supplementary Material