What is the Sleeper Effect

The sleeper effect is studied by social psychology as it relates to repetitive advertising and, more specifically, attitude change and delayed persuasion. This effect is a psychological phenomenon that relates to persuasion.

It is a delayed increase in the effect of a message that is accompanied by a discounting cue. A discounting cue being some negative connotation or lack of credibility in the message.

A positive message may evoke an immediate positive response which decays over time, the sleeper effect refers to a delayed positive response that is maintained over time. The field most impacted by the sleeper effect is advertising, often for a product an individual does not really need.

Carl Hovland, American psychologist, is credited with being the first research scientist to propose the sleeper effect in the late 1940s. Hovland described the sleeper effect after studying the effects of Frank Capra’s recruitment film.

The effect was first noticed among US Army soldiers exposed to army propaganda. It was hypothesized that over time the soldiers forgot that the message was propaganda.

During World War II, a group of United States soldier recruits was shown a recruitment film titled The Battle of Britain. When the soldiers were shown the film again nine weeks later, perhaps surprisingly, it seemed to emotionally impact the soldiers more than when it was originally shown to them.

Thus, it seemed as if the soldiers were more convinced of the film’s inspiring message after they had ” slept on it” or ” thought about it” for a while.

The effect has been widely studied but notoriously difficult to reproduce, which leads some psychologists to completely doubt its existence.