Dit komt uit een overzichtsartikel van psycholoog Merikle van de University of Waterloo (Canada; deze universiteit heeft een erg goede psychologie dept.):
"Over the years, some extraordinary claims have been made concerning the power of subliminal perception. Perhaps the most widely known claim was made in 1957 by James Vicary, a market researcher. He claimed that over a six-week period, 45,699 patrons at a movie theater in Fort Lee, New Jersey were shown two advertising messages, Eat Popcorn and Drink Coca-Cola, while they watched the film Picnic. According to Vicary, a message was flashed for 3/1000 of a second once every five seconds. The duration of the messages was so short that they were never consciously perceived. Despite the fact that the customers were not aware of perceiving the messages, Vicary claimed that over the six-week period the sales of popcorn rose 57.7% and the sales of Coca-Cola rose 18.1%. Vicary's claims are often accepted as established facts. However, Vicary never released a detailed description of his study and there has never been any independent evidence to support his claims. Also, in an interview with Advertising Age in 1962, Vicary stated that the original study was a fabrication. The weight of the evidence suggests that it was indeed a fabrication".
"A common theme that links all extraordinary claims regarding subliminal perception is that perception in the absence of an awareness of perceiving is somehow more powerful or influential than perception that is accompanied by an awareness of perceiving. This idea is not supported by the results of controlled laboratory investigations of subliminal perception. Rather, the findings from controlled studies indicate that subliminal perception, when it occurs, reflects a person's usual interpretations of stimuli. Furthermore, there is no evidence to suggest that people initiate actions on the basis of subliminal perception. The weight of the evidence indicates that people must be aware of perceiving stimuli before they initiate actions or change their habitual reactions to these stimuli. Thus, although subliminal perception may allow us to make accurate guesses regarding the characteristics of stimuli, subliminal perception cannot lead a person to drink Coca-Cola or to eat Ritz Crackers, and it cannot be used effectively to improve a person's tennis skills or to cure a person's bad habits".
Meer bewijs voor de "broodje aap" status van de cola en popcornverhalen:
http://www.snopes.com/business/hidden/popcorn.asp