In 1957, a gentleman by the name of James Vicary created a new concept: Subliminal advertising. He flashed the words “Eat Popcorn” and “Drink Coca-Cola” for a fraction of a second during a film, and claimed increases in sales of these products of 18% and 57% respectively.

But, there’s one other thing that bugged me about that ‘study’. The name of the film. It was called ‘Picnic’. I’ve never seen this film, and I don’t know if you have, but I find it hard to imagine that there weren’t multiple scenes of gratuitous eating and drinking in it! Could this possibly have a more powerful effect than a few words, flashed for only 1/300th of a second?

Maybe, but this is all academic, as Vicary supposedly admitted to fabricating his results. Still, I think my general point is valid.

Most people would see subliminal messages as some kind of slimy, dirty, underhanded advertising trick, right up there with spam emails. However it’s apparently OK to use every other persuasion technique in the book to get you to buy something: celebrity endorsements which bring authority and social proof. Free gifts to trigger the reciprocity principle. Short-term sales to activate the scarcity principle. Are these things underhanded? Oh no, these are all fine, but throw in a capitalised word for 1/300th of a second, and there’ll be riots!

Advertisers are throwing the big guns at us, and we’re worried about the little pee-shooter in the corner. I think it’s the feeling of being cheated; that they are not playing by the rules. Manipulate us, sir, but not behind our backs; that would be wrong.

But is this something we should be worried about? Probably not. In 1992, a review of over 200 studies of subliminal advertising concluded that there is very little evidence to support the idea that subliminal advertising can influence our behaviour. (1)

But sometimes you’ll hear stories of people that were ‘influenced’. You’ve got to be careful that you’re not seeing what you want to see; adapting your interpretation of your experience to fit your beliefs, rather than the other way around. Vicary publicly announced that he’d run another subliminal message, this time on live TV. He flashed the phase “telephone now” during a program. Call-in rates didn’t increase, however some viewers reported that they had the uncontrollable urge to get a drink or use the toilet. Interesting. Because that never happens when people aren’t flashing subliminal messages at you!

So how did we start at Vicary’s supposedly fabricated first study, go through the failed second one, the 1992 rebuke, and still end up at, for example, the telegraph, September 2009: “Subliminal advertising really does work, claim scientists.”

Claim scientists? Hang on a second. Weren’t the scientists the ones saying subliminal messaging in advertising DOESN’T work? What’s going on here?

Well there’s a difference between subliminal messages changing someone’s behaviour, and the subliminal perception of a message. Very important distinction. The study reported by the telegraph asked people to rate whether the word was positive or negative; it didn’t look into behavioural consequences of that perception.

We came across a similar study in the priming article. People seem unconsciously aware of whether subliminal messages are positive or negative, but it takes more overt priming to bring behavioural consequences. Not much more; but read the priming article for more information on that. This brings me nicely back to my point: Don’t worry about subliminal messages in advertising, they probably aren’t going to effect you. It’s the very blatant, obvious stuff you should be worrying about!

Maybe blatant persuasion and propaganda is something we’ll look into another day. I’d cover it now, only I have the strangest urge to go buy some popcorn and coca-cola…

References:

(1) Pratkanis, A & Aronson, E. (1992). Age of Propaganda: The Everyday Use and Abuse of Persuasion. NY: W.H. Freeman