The sleeper effect identified by psychologist Carl Hovland refers to the "hidden" effect of a propaganda message even when it comes from a discredible source. A psychologist is a social scientist who studies psychology, the study of the human mind, thought and human behaviour. ... Carl Iver Hovland (1912-1961) was a psychologist working primarily at Yale University and the US Army during World War II who studied attitude change and persuasion. ... Jump to: navigation, search North Korean propaganda showing a soldier destroying the United States Capitol building. ...

Hovland studied the effects of the Frank Capra World War II propaganda film Why We Fight on US soldiers. He found that when the soldiers found the source of a piece of information discredible, they would discount it. However, after an amount of time soldiers would forget where a given message originated, but they would still remember the message itself. In this way, information from a low credibility source could increase in effectiveness. Frank Capra Frank Capra (May 18, 1897 – September 3, 1991) was an American film director and a major creative force behind a number of highly popular films. ... Jump to: navigation, search World War II was a truly global conflict with many facets: immense human suffering, fierce indoctrinations, and the use of new, extremely devastating weapons such as the atom bomb World War II, also known as the Second World War, was a mid-20th-century conflict that... A propaganda film is a film, often a documentary, produced for the express purpose of propaganda: convincing the viewer of a certain political point. ... Why We Fight is the name of a propaganda series of seven newsreels commissioned by the United States government during World War II to convince the U.S. public about the need for American intervention. ...

In one experiment, students read arguments about nuclear power. One group was told the arguments came from an American nuclear scientist, and the other was told that they came from the Soviet newspaper Pravda. Only the first group showed attitude change in the short term. After several weeks, once the supposed sources of the information had been forgotten, both groups showed the same degree of attitude change. Jump to: navigation, search This article is about power derived from nuclear reactions. ... Jump to: navigation, search State motto (Russian): Пролетарии всех стран, соединяйтесь! (Transliterated: Proletarii vsekh stran, soedinyaytes!) (Translated: Workers of the world, unite!) Capital Moscow Official language None; Russian (de facto) Government Federation of Socialist republics/ Communist state Area  - Total  - % water Largest on the planet 22,402,200 km² ?% Population  - Total  - Density 3rd before collapse... Jump to: navigation, search This article treats the Soviet/Russian newspaper. ...

However, note that the sleeper effect has since had something of a checkered history since its original conception. The effect is not considered nearly as strong or reliable as once thought, and much of the original research on the effect is no longer cited in support of its existence.

See also: mere exposure effect. The mere exposure effect is a psychological artifact well known to advertisers: people express undue liking for things merely because they are familiar with them. ...

References

Original research:

• Hovland, C. I., Lumsdaine, A. & Sheffield, F. (1949). Experiments on mass communication. Princeton, NJ: Princeton University Press.
• Hovland, C. I., Janis, I. L. & Kelley, H. H. (1953). Communications and persuasion: Psychological studies in opinion change. New Haven, CT: Yale University Press.

More recent/critical research:

• Kumkale, G. T., & Albarracín, D. (2004). The sleeper effect in persuasion: A meta-analytic review. Psychological Bulletin, 130, 143-172.

PDF

• Gillig, P. M., & Greenwald, A. G. (1974). Is it time to lay the "sleeper effect" to rest? Journal of Personality and Social Psychology, 29, 132-139
• Pratkanis A. R., Greenwald, A. G., Leippe, M. R., Baumgardner, M. H. (1998). In search of reliable persuasion effects: III. The sleeper effect is dead. Long live the sleeper effect. Journal of Personality and Social Psychology, 54(2), 203-18.
• Greenwald, A. G., Pratkanis, A. R., Leippe, M. R., & Baumgardner, M. H. (1986). Under what conditions does theory obstruct research progress? Psychological Review, 93, 216-229. PDF

External links

• Changingminds.org: sleeper effect