Subliminal seduction gets a second glance

The new respectability of subliminal persuasion research

Posted Jan 27, 2011

Recently, I holed up indoors with my family watching old sci fi movies, including The Puppet Masters, a story about alien blobs that sit on people's backs and wire themselves into human nervous systems, controlling their hosts' thoughts and actions. Not a great movie, but it was its lack of originality that got me thinking. The science fiction genre is busting at the seams with horror scenarios in which individuals become absorbed in some collective mind that wipes out their capacity for free will: You have your invading body snatchers, your Borg (resistance is futile) and your Cylons (with their many copies). Even my childhood favorite A Wrinkle in Time has the heroic Meg tesseracting to save her little brother from having his brilliant and unusual mind vacuumed up by the throbbing, pulsing centralized brain of IT. If sci fi serves as a window into the anxieties of an age, then it would appear that mind control and its ensuing loss of individuality is our great cultural nightmare.

Of course, our political and economic systems rest on the narrative of freedom of individual choice, so it's not surprising that as a culture, we should experience spasms of angst just thinking about assaults on these freedoms. And so it is with any persuasion tactics that hint of mind control.

Historically, fears about mind control in the hands of marketers peaked several decades ago. In 1957, Vance Packard published his best-seller The Hidden Persuaders, in which he described how a New Jersey movie theater had flashed subliminal messages to "Eat popcorn" and "Drink Coca-Cola", thereby causing sales at the snack bar to spike. James Vicary, a self-promoting market researcher, jumped in to take credit for the "experiment". And a number of years later, an overwrought Wilson Bryan Key wrote Subliminal Seduction, in which he claimed that advertisers embedded images of sex, death, and bestiality in their ads to manipulate people into buying their products. Claims like these quickly gave birth to cottage industries of consumer education programs, marketing consultancies and subliminal self-help tapes.

Turns out, though, that much of the hype was a sham. Vicary's "experiment" appears to have been an outright hoax, and the subliminal self-help industry was exposed as junk science. The idea of subliminal advertising for the most part joined the garbage heap upon which are piled fears about satanic messages being played backwards in Led Zeppelin songs, and sightings of the Virgin Mary on cheese sandwiches (both of which got a pretty debunking in a 2006 TED talk by Michael Shermer). The dust settled, public paranoia about advertising practices abated, and in scientific circles, a professed interest in subliminal advertising came to be about as respectable as wearing scarlet lipstick and fishnet stockings to an academic conference—or conducting research about ESP, for that matter.

And so it was that no great scandal erupted during the 2000 Bush/Gore presidential election campaign, when the Republican Party placed an ad that attacked Al Gore's proposed health care policies by arguing that under Gore's plan, bureaucrats rather than individual patients and their doctors would have control over prescriptions. As the voice-over uttered the damning words "The Gore Prescription Plan: Bureaucrats Decide," the word RATS was very briefly superimposed on the screen in large letters just before being replaced by the text Bureaucrats Decide. The word appears right around the threshold of perception—if you watch the ad, paying very close attention, you just may be able to see it.

Bush claimed that this was an accidental result, and brushed aside accusations of subliminal advertising as "weird and bizarre" conspiracy theories. When pressed, Alex Castellanos, the ad's creator, said he flashed part of the word bureaucrats as a "visual drumbeat" to create visual interest, and insisted it was coincidental that the letters happened to spell rats. Though the media reported on the ad, and the Federal Communications Commission launched a somewhat limp investigation, the event was shrugged off by many on the grounds that "everyone knows subliminal advertising doesn't work."

But as a researcher of language, I couldn't quite get why it was obvious that the subliminal message wouldn't work. On the face of it, subliminally associating the word RATS with Democrats might seem no more plausible as a strategy than recruiting followers for Satan by means of backwards song lyrics. But if you know something about how linguistic messages are actually processed by human minds, it becomes harder to spread your skepticism around evenly between the two. Human beings are highly unlikely to extract the meanings of sentences spoken or sung backwards, let alone do so automatically and unconsciously. One of the most basic facts about human language processing is that we're firmly bound by the linearity of language in time, meaning that we process it forwards with supreme efficiency, but find it mind-bendingly hard to do so backwards. On the other hand, it's been known for decades that people do register the meanings of words flashed so briefly that they're unaware of them, and that these meanings affect their cognitive responses. In fact, subliminal presentation of words is a standard, run-of-the-mill tool pulled out by language scientists to test arcane theories of language that have nothing to do with mind control.

All of which made me think that the received wisdom about subliminal messaging was being tarred by too broad a scientific brush; some techniques had no hope of fitting in with facts about human cognition, but others were much more reasonable candidates.

Apparently, I'm not the only one who wondered. In 2008, psychologists Joel Weinberger and Drew Westen carried out their own experimental RATS campaign, and found that subliminally flashing RATS (as opposed to a word like STAR, or symbols like XXXX) before showing study volunteers a photo of a fictional political candidate caused them to report a more negative impression of that candidate.

A lot has happened in psychological science in the decade since the Bush/Gore election. Weinberger and Westen's study is now only one among many that have found that people's attitudes and behavior can be swayed by cues that they have no awareness of, or that they don't believe to be relevant to their behavior. Here's a fistful of exotic findings from the last few years of research:

John Bargh and colleagues have run dozens of studies in which they've shown that human behavior can be "primed" in various ways—people became more polite after doing puzzles with words that relate to courteousness than with words that are associated with rudeness; they behaved more aggressively after the subliminal flashing of images that evoke stereotypes of aggression (such as the image of a black man); they behaved more altruistically when sitting in a room with a backpack on the table, than in a room with a briefcase.

As discussed in a recent post by Art Markman, in a study by Ran Hassin and colleagues, Israeli citizens moderated their polarized political opinions after the subliminal presentation of the Israeli flag, which presumably evoked feelings of national unity.

A study led by Grainne Fitzsimons revealed how a computer company can condition you to "Think Different": The subliminal presentation of the Apple logo resulted in better performance on a creativity test than subliminal presentation of the IBM logo.

And can the brief flashing of a brand name induce a craving for the product? In a study by Johan Karremans, study volunteers who "saw" brief flashes of the words "Lipton Ice" reported that they would prefer this drink to a competitor's, but only if they were already thirsty at the time they were exposed to the subliminal message.

What's emerging from this fascinating scientific literature is that subliminal messages often can affect thoughts and behavior, at least for a short period of time, and at least if the message aligns with the audience's state of mind at that time. But there's no unique and magical power to messages that are too brief to be seen; their effect is just one part of our human tendency to suck up, process, and act on as many cues in our environment as we possibly can, responding to them without necessarily running them through our filter of conscious awareness.

In truth, most of human cognition hums efficiently along below the level of our awareness without any special direction or interference from our conscious wills. Acting on fleeting messages we don't know we've seen is really no different from any one of the countless things we do automatically and without deciding to do: pulling up the meanings and emotions linked with words in memory, intuiting that someone is trustworthy because his regional accent signals that he's a member of our social tribe, or feeling reassured by a doctor's confident body language and style of speech.

In the end, it's not so much that persuaders need to violently fuse their wills into our spinal columns; it's more that our own minds—unknown to our conscious selves—invite them in.