Name: Behavioural nudges.

Age: Nudge theory was popularised by the 2008 book Nudge: Improving Decisions About Health, Wealth and Happiness, by Richard Thaler and Cass Sunstein. But the term nudge had been used in cybernetics, the science of communications and automatic control systems, in the 1990s.

And it means? As the title of that book suggests, we are talking about using psychological tactics to steer people gently towards making better decisions.

Can you give me an example, please? In 2012, researchers at Cornell University, New York, published a study that found students at a school cafeteria were more likely to pick healthy snacks, such as apples and carrots, if these were made more convenient and put at eye level. The results helped spread the idea of the nudge.

And proved that the theory works. Yay, healthy kids. Not so fast.

You just said the kids ate the carrots. No, I didn’t, and they didn’t. One part of the experiment was that the Cornell team watched what happened after the kids had paid for their food.

The carrots weren’t eaten? They were binned. And the nudged ended up eating the same as the un-nudged.

That’s actually worse because of the waste. True. It also raises questions about whether nudging has any effect or benefit in the long run. Now, marketing academics Evan Polman from the University of Wisconsin-Madison and Sam Maglio from the University of Toronto have done some research into this and written about it in the Wall Street Journal.

What did they do? It was an experiment in which participants were given opportunities to sign up to a website in order to get a daily fix of trivia, and they used various nudging strategies to encourage some of them. The details of the study aren’t so important to Pass Notes but what they found was that a higher percentage opted for the option they were nudged towards.

Er … doesn’t that mean the nudging works? Wait, because that’s what they did – they waited. For eight months! And then they found the nudged participants were visiting the site 42% less often than people who hadn’t been nudged.

So long-term, the nudging could have a negative effect? In this case, yes. It was a similar story with another experiment they did: people who were nudged towards getting a plant were less likely to care for it.

The plants died? I’m afraid so. Sixteen per cent sooner than the plants chosen by those who didn’t have to be nudged.

Almost as if a decision that comes from you (rather than being pushed, however gently, towards it) might mean more? Almost.

Do say: (As Polman and Maglion conclude): “Nudges may be a great first step. But that’s all they are: a first step.”

Don’t say: “Nudge nudge, wink wink.”