Sleeper effect

Over time, however, their newly formed attitudes seem to gravitate back toward the opinion held prior to receiving the message, almost as if they were never exposed to the communication.

Despite a long history, the sleeper effect has been notoriously difficult to obtain or to replicate, with the exception of a pair of studies by Gruder et al. (1978).

[5] However, Cook and his associates responded by suggesting that previous studies failed to obtain the sleeper effect because the requirements for a strong test were not met.

[7] According to the dissociation interpretation, a sleeper effect appears to happen when a convincing message is conferred with a discounting cue (such as a low-credible source or counterargument).

A sleeper effect occurs because of an impulsive dissociation of a message and a discounting cue over time (contrasting to a simple forgetting of a source).

[8] The sleeper effect was first identified in US Army soldiers during World War II, after attempts to change their opinions and morals.

Carl Hovland et al. measured the soldier’s opinions five days or nine weeks after they were shown a movie presentation of army propaganda.

Hovland and his colleagues introduced a program of research to study how recall of the message and the source persuaded the sleeper effect.

Hovland, Lumsdaine, and Sheffield (1949) first discovered the effect by a well-known study that demonstrated the delayed impact of a World War II propaganda movie on American soldiers.

After examining the results, they initially hypothesized that forgetting of the discounting cue (in this case, the non-credible source) was causing the effect.

Despite evidence for the sleeper effect from this series of studies, the recall measures indicated that recipients could still remember the non-credible sources of the messages at the time of the delayed follow-up.

As the association weakens over time, rendering the cue less accessible in relation to the communication topic, there may be a delayed increase in persuasion as long as the message arguments are still memorable.