The ironic effect of no-smoking signs

Scientists at Oxford University found that no-smoking signs have an “ironic effect” on smokers, driving them to react and think of tobacco, the researchers said.

“You get ironic effects when you couple information that people perceive with negation,” researcher Brian Earp said.

“When I say ‘don’t think of a pink elephant’, I have just put the thought of a pink elephant in your head,” Earp was quoted as saying by the Daily Mail.

He said: “A lot of public health messages are framed in a negative way—say no to drugs, don’t drink and drive, no smoking. No-smoking signs in particular are everywhere. If you are a smoker walking down a street you’re likely to pass five or six of these signs in windows or on doors. If you have a chronically positive attitude to smoking this could boost your craving.”

To test the theory, Earp and his team first primed a group of smoking volunteers from a town in New England in the US, by showing them a number of photographs. Some included a no-smoking sign in the background or at the edge of the image, while others had the signs edited out.

Next, the same volunteers took part in a “joystick test” looking at their reactions to a series of screen images.

The technique is widely used to assess instinctive tendencies to embrace or avoid certain stimuli.Moving the joystick away is associated with avoidance, while drawing it towards the body indicates a desire to bring the stimulus closer.

In a series of experiments, the researchers showed that participants who had earlier been shown no-smoking signs were more drawn to smoking-related images such as ashtrays and cigarettes.