Most people will have heard of the “nudge unit” – a crack team of behavioural economists installed in Downing Street which has the power to wire policy directly into our frontal cortices, using only cutting edge neuroscience and door-to-door leafleting.

For those that haven’t, “nudging” is an evidence-based strategy that aims to influence people’s behaviour towards certain of David Cameron’s more benign policies, such as cutting energy use and reducing obesity. It’s a canny way of motivating people without offering financial reward. To get people eating healthily, for instance, it helps to put apples, rather than crisps, on eye-level shelves in shops.

At base, however, “nudging” is just a scienced-up and buzzworded-down way of saying “advertising”. The trouble for Cameron is that, for every penny spent marketing his policies through nudge, thousands more are spent by the advertising industry to encourage us to go in what is often precisely the opposite direction. So, it’s not surprising that the effects of nudging have as yet been lukewarm.

Part of the problem is that the nudgers aren’t yet fully realised advertising men. Advertisers know the importance of targeting an audience, but nudging is very one-size-fits-all. What is perhaps more troubling for Cameron is that his core audience and his core voters are not often the same people.

A US study by Dora Costa and Matthew E Kahn of the University of California, Los Angeles showed that conservatives are far less susceptible to nudges in the direction of energy conservation than liberals. Researchers designed leaflets that let households know how much energy they were using compared to their peers (with a smiley face if they were using less and a frowny face if they were using more), and handed them out to a mix of conservative and liberal households. While this nudge usually lowered carbon consumption in liberal households, it actually had the opposite effect in conservative homes.

The researchers thought that the “boomerang” effect had been much stronger among conservative voters. If they saw they had used less energy than others (smiley face), they were likely to increase their energy consumption to catch up. This was because they had not been on board with the basic energy saving  ideology from the start; the leaflet merely nudged them towards the norm.

Cam can’t

A nudge unit is, all in all, an odd choice for Cameron. Not only are conservative voters less likely to be on board with the policies, which generally are more tailored to appeal to the community-minded, they are also more likely to act in defiance against any such “nannying” moves.

So, if they want to extend their influence, nudgers need to take more lessons from the advertising industry. This is inconvenient for them, as they like to brand themselves as a breed apart. Nudging itself, you see, is an industry – and markets itself sagely, knowing our weakness for all things science. It’s not science, though: it’s leafleting, and right now it’s leafleting all the wrong doors.