Anthony R. Pratkanis Carnegie-Mellon University
Anthony G. Greenwald Ohio State University
Attitude change agents are often concerned about the fruits of their labor after the passage of time. A government agency charged with litter control hopes that its anti-litter campaign will be effective long after its leaflets have been discarded. An advertiser hopes that the impact of a TV commercial persists through the interval between presentation and subsequent shopping trip. The pulpit preacher seeks a conviction of everlasting salvation and, not just momentary bliss from the congregation.
For the most part, research on persuasion finds that whenever opinion change occurs, it usually dissipates over time (see Cook & Flay, 1978 for a review). Over 50 years ago, researchers found a pattern of data opposite to this typical trend. This chapter tells the story of the history of this effect -- termed the sleeper effect in persuasion.
In 1928 the Motion Picture Research Council commissioned a series of studies to investigate the effects of motion pictures on children. Peterson and Thurstone ( 1933) took up their charge by showing films about the Germans, gambling, prohibition, and other social issues to school children living in the midwest. They found that many of the films did indeed change children's attitudes with effects diminishing slightly over time. However, a pro-German