"What do you think about if I say 'DON'T think about pink elephants?!" demanded the Professor of Organizational Psychology. There was a silence, while we, the students, tried very hard not to think about pink elephants. The result was...

"Ah, yes, red balloons!" said a colleague, when I told her the story later. "Don't think about red balloons..."

Whether you try this game with pink elephants, red balloons, purple tigers or green Martians, the result is always the same: the visual part of our brain does not distinguish between positive and negative instructions. To the brain, a pink elephant is just the same as a not-pink elephant. And if a balloon is not-red, then what is it? How do you picture it?

Let's imagine a few, familiar examples. The dependable best friend, trying to console a teenager who's just been abandoned by her boyfriend, offers this advice: "Put him out of your mind, forget about him...try to think about something else. But whatever you do, don't call him!!" Even with the words "Don't call!" ringing in her brain, the teenager still reaches for the phone the moment she's on her own. So what does she actually picture in her mind's eye? She pictures herself, (not) reaching for the phone. The image is strong, and before she knows it, she's dialing frantically. With predictably disastrous results...

An HR manager, seeking to reassure an anxious workforce, makes this announcement: "Don't worry about the future of your jobs! Don't listen to malicious gossip spread by our competitors, and please, pay no attention to rumors circulating in the press!" Strange, then, that everyone rushes out to buy a newspaper in their lunch break.

We've all found ourselves at some time trying to protect a friend or colleague, to build them up, to get them to say 'No', to put iron in the soul. But when we say: "Don't let them get away with it!" "Don't let them manipulate you!" or "Don't let them shout you down!" are we being as supportive as we think? Perhaps at a conscious level, our friend may try to take the action we prescribe, especially when the instruction seems so obviously to their advantage. However, on a deeper, psychological level the effects may well be the opposite - we could be chipping away at their self esteem and self confidence.

It is clear that when we give people advice, sometimes they follow it, sometimes they ignore it, and sometimes they do the complete opposite. If we tell someone not to jump off a cliff, they may well picture the idea of leaping to their deaths, but are highly unlikely to actually do so. Basic self preservation kicks in.　

In less extreme cases however, we should be aware of the subtle power of emotional or visual ideas, and how the deeper, mental impact may often be the opposite of what we intend. Of course, in the case of reverse psychology, people sometimes do this deliberately.

So, if we actually DO want an audience to think about pink elephants, but we can't admit it, perhaps for legal, personal or political reasons, then what better way to achieve our goal than to shout: "DON'T think about pink elephants!"?