A subliminal message is a signal or message designed to pass below (sub) the normal limits of perception. For example it might be inaudible to the conscious mind (but audible to the unconscious or deeper mind) or might be an image transmitted briefly and unperceived consciously and yet perceived unconsciously. This definition assumes a division between conscious and unconscious which may be misleading; it may be better to say that the subliminal message (sound or image) is perceived by deeper parts of what is a single integrated mind.
In the everyday world, many have claimed that subliminal techniques are used in advertising and for propaganda purposes but officially it is denied. In Russia, however, there have been reports of subliminals. For example, Pravda have had stories about the discovery of subliminal messages in advertising from the West.
Origin of the Term
The term subliminal message was popularized in a 1957 book entitled The Hidden Persuaders by Vance Packard. This book detailed a study of movie theaters that supposedly used subliminal commands to increase the sales of popcorn and Coca-Cola at their concession stands. However, James Vicary (the author of the study) later admitted the study was fabricated.
In 1973 Wilson Bryan Key's book Subliminal Seduction claimed that subliminal techiques were in wide use in advertising. The book contributed to a general climate of fear with regard to Orwellian dangers (of subliminal messaging). Public concern was enough to lead the Federal Communications Commission to hold hearings and to declare subliminal advertising "contrary to the public interest" because it involved "intentional deception" of the public.
In spite of the popular belief that subliminal messages are widely used to influence audiences, there is little evidence that the technique has ever been used on a mass audience (other than its occasional use by artists who use it to make an artistic statement). There is no evidence that subliminal messages have any effect at all on a viewer or listener, and the current consensus among marketing professionals is that subliminal advertising is ineffective and can be counter-productive. The theory underlying subliminal messages is often considered to be pseudoscience. However, the concept of subliminal messages is very popular among conspiracy theorists, and most people in media-saturated areas (such as the United States) are familiar with the term.
A number of fringe elements in society have made occasional claims that subliminal messages can be found in various forms of popular entertainment. Popular claims of subliminal commands include the supposed use of "backward messages" in rock and roll songs. Conservative activist Donald Wildmon has claimed that The Walt Disney Company inserted the subliminal command "SEX" into the animated film The Lion King (see that article for more information on this). Mainstream authorities have generally ignored these claims due to the dubious reputations of their authors.
Subliminal perception or cognition, if it exists, can be considered a subset of unconscious cognition where the forms of unconscious cognition also include attending to one signal in a noisy environment while unconsciously keeping track of other signals (e.g one voice out of many in a crowded room) and tasks done automatically (e.g. driving a car).
An important question about subliminal perception is: How much of the unattended or unconscious signal or message is perceived? That is, is the whole message sensed and fully digested or perhaps only its main and simpler features? There are at least two schools of thought about this. One of them argues that only the simpler features of unconscious signals could be perceived. The second school of thought argues that unconscious cognition is comprehensive and that much more is perceived than can be verbalized.
Various types of studies of subliminal perception have been conducted. A related field is the question of whether anaesthetized patients are completely unaware whilst apparently completely asleep/unconscious.
Proponents of the power of subliminal messages claim they gain influence or power from the fact that they circumvent the critical functions of the conscious mind, and therefore subliminal suggestions are potentially more powerful than ordinary suggestions. This route to influence or persuasion would be akin to auto-suggestion or hypnosis wherein the subject is encouraged to be (or somehow induced to be) relaxed so that suggestions are directed to deeper (more gullible) parts of the mind; some observers have argued that the unconscious mind is incapable of critical refusal of hypnotic or subliminal suggestions.
However, research findings do not support the conclusion that subliminal suggestions are peculiarly powerful, or even have any effect at all.
Subliminal Messages in Advertising
A form of subliminal messaging commonly believed to exist involves the insertion of "hidden" messages into movies and TV programs. The concept of "moving pictures" relies on persistence of vision to create the illusion of movement in a series of images projected at 23 to 50 frames per second; the popular theory of subliminal messages usually suggests that subliminal commands can be inserted into this sequence at the rate of perhaps 1 frame in 25 (or roughly 1 frame per second, with a duration of about 1/25 of 1 second). The hidden command in a single frame will flash across the screen so quickly that it is not consciously perceived, but the command will supposedly appeal to the subconscious mind of the viewer, and thus have some measurable effect in terms of behavior.
Another "subliminal" message technique is supposedly to embed into a printed advertisement certain messages or symbols which are subtle and perceived only by the unconscious mind, either to communicate a message or to increase the attention paid to the printed ad. This technique, as with subliminal TV advertising, is not generally regarded as effective.
As to the question of whether subliminal messages are widely used to influence groups of people e.g. audiences, there is no evidence to suggest that any serious or sustained attempt has been made to use the technology on a mass audience. The widespread reports that arose in 1957 to the effect that customers in a movie theatre in New Jersey had been induced by subliminal messages to consume more popcorn and more Coca-Cola were almost certainly false. The current consensus among marketing professionals is that subliminal advertising is counter-productive. To some this is because they believe it to be ineffective, but to most it is because they realise it would be a public relations disaster if its use was discovered. Many have misgivings about using it in marketing campaigns due to ethical considerations.
During the 2000 U.S. presidential campaign, a television ad campaigning for Republican candidate George W. Bush showed words (and parts thereof) scaling from the foreground to the background on a television screen. When the word BUREAUCRATS flashed on the screen, one frame showed only the last part, RATS. Democrats promptly asked the FCC to look into the matter, but no penalties were ever assessed in the case. The effect this had on the overall presidential race was unclear; the Democrats and Al Gore received ridicule for finding malicious intent in something that could have been a simple mistake; the Republicans received ridicule for the lack of attention to detail and Bush's mispronunciation of "subliminal" (it came out as "subliminable"). (It bears mentioning that the "subliminal message" is easily viewable when the ad is played at regular speed. If the message were truly subliminal, that would not be the case.)
- "Over the years there have been literally hundreds of studies"..."these studies show that considerable information capable of informing decisions and guiding actions is perceived even when observers do not experience any awareness of perceiving". Philip Merikle, Department of Psychology, University of Waterloo.
- Urban Legends: Subliminal Advertising (http://www.snopes2.com/business/hidden/popcorn.htm)
- 1984 testimony about subliminal messages to the Federal Communications commission (http://www.parascope.com/articles/0497/sublimdc.htm)
- CNN article on 2000 presidential campaign "rats" TV ad (http://www.cnn.com/2000/ALLPOLITICS/stories/09/13/bush.ad/)
- Scientific Consensus and Expert Testimony: Lessons from the Judas Priest Trial (http://www.csicop.org/si/9611/judas_priest.html/)
- Subliminal messages in music (http://www3.telus.net/jefmil/stairwaybackwards.htm)
- Subliminal Perception: The nature of a controversy, N.F.Dixon, McGraw-Hill, New York, 1971.
- Psychological Investigations of Unconscious Perception, Journal of Consciousness Studies, P.M Merikle and M. Daneman, 1998.
- New Look 3: Unconscious Cognition Reclaimed, American Psychologist, 47, Anthony W. Greenwald, 1992.
- Holender, D. (1986). Semantic activation without conscious identification in dichotic listening, parafoveal vision, and visual masking: A survey and appraisal. Behavioral and Brain Sciences, 9, 1-23.