Is it time to lay the sleeper effect to rest?

The quot;sleeper effect quot; has been defined as a delayed increase in the persuasive impact of a communication from a source low in credibility. This effect failed to appear in the present series of seven replications (total N = 656) of a sleeper effect experiment. However, the effectiveness of communications at-tributed to a source high in credibility did significantly decrease with passage of time when subjects were unprepared to counterargue with the communica-tion. On the basis of these results and a retrospective review of related stud-ies, it was concluded that the latter effect, by itself, could account satisfac-torily for previous findings that source credibility effects dissipate or disappear with passage of time. As many undergraduate psychology students have by now learned, the quot;sleeper effectquot; is an established phenomenon in the attitude change literature. This effect is said to occur when a communication from a source of low credibility has a greater persuasive impact after some time delay than on original exposure. The communication works, that is, while the audience quot;sleeps quot; on it. Descriptions of the sleeper effect may be found in a variety of social psychology texts. Examination of the authors bookshelves indicated that approximately 75 % of recent survey texts make explicit reference to the sleeper effect as an established phenomenon. The negative results of seven replications of a sleeper effect experiment to be reported here prom~ted the authors to reexamine the empirical literature on this phenomenon. Remarkably, this retrospective review led to the conclusion that the sleeper effect has never had a truly satisfactory emnirical basis. The origin21 report of a sleeper effect by Hovland, Lumsdaine, and Sheffield (1949) was based on only a subset of the opinion items they