Richard Petty and John Cacioppo's elaboration likelihood model says a message can change minds by two routes. On the central route, people think hard about the arguments. On the peripheral route, they go by surface cues, like a famous face. Set up an ad and an audience. The model predicts which road wins and how long the change lasts.
Which road does the message take?
The thicker road carries more of the persuasion. The chart shows how much of the attitude change is left after each week.