This study uses psychological reactance theory as a framework for designing effective emergency preparedness messages. Psychological reactance is the motivational state that occurs when individuals perceive their freedom to be threatened. From the standpoint of persuasive message design, reactance is an undesirable outcome that should be avoided whenever possible.

Participants (N = 174) were randomly assigned to view 1 of 2 emergency preparedness messages (choice-enhancing language [“the choice is yours”] vs choice-restricting language [“you must”]) in a between-subjects-posttest-only online survey experiment.

Structural equation modeling revealed that choice-restricting language resulted in greater freedom threat and subsequent reactance. Reactance resulted in a diminished attitude and subsequent intention to prepare an emergency kit.

Public health practitioners would benefit from the inclusion of choice-enhancing language in their public communications, alongside the exclusion of choice-restricting language. Pretesting of messages is recommended to avoid eliciting reactance and subsequent boomerang effects.