Although James Vicary’s 1957 experiment, where he said that he subliminally broadcast the words “Drink Coca-Cola” and “Eat Popcorn’’ to influence movie-goers’ purchase behaviour, was later shown to be a hoax, there is now more and more evidence to suggest that under certain conditions, subliminal persuasion can indeed influence behaviour.
Research published in Neuron in September, 2008, and the Journal of Experimental Social Psychology in 2005 and 2006, suggests that subliminal priming will work under certain conditions. In general, the conditions were that the prime should be goal-relevant, and respondent should be motivated to pursue that goal. In one experiment, respondents who were exposed to a subliminal message (i.e., below their awareness threshold – at 23ms or 23/1000 of a second) that was thirst-related (e.g., words such as thirst, dry) were more likely to drink more after this exposure, than those who were subliminally primed with neutral words (e.g., pirate, won).
In another experiment, participants who were already thirsty (i.e., they hadn’t had anything to drink for 3 hours) were subliminally primed with an image of Lipton Ice, and were more likely to choose that brand when offered a selection of drinks, than those who were primed with neutral images.
Regardless of these findings, psychologists and consumer behaviour specialists are coming to realise that there is more to persuasion than meets the perceived (and attended) eye.
It is becoming clearer that advertising works on many levels, and bodies such as ACMA, along with advertisers and policy makers, need to recognise that even incidental exposure via billboards or posters, is likely to have some impact over our eventual behaviour, even though we may not be aware of their influence. This is of particular importance in situations when vulnerable consumers, such as children, may be exposed to an image, and despite their understanding of its intent, may not be in a position to control its eventual effect on their behaviour.