The referendum on Scottish independence was announced last year. Alex Salmond, leader of the SNP and the Yes movement, was quick to propose a question.

He plumped for: "Do you agree that Scotland should be an independent country?"

Salmond, presumably with a team of very clever copywriters and pollsters, had created a brilliantly biased question. It’s what we’d call a nudge, a positive call-to-action that gets readers to go along a subtly suggested path. If it had gone unnoticed, it would have really helped the Yes campaign.

Of course it didn’t. The most succinct critique came from Martin Boon, ICM's research director for social and government research. He told the Telegraph, This is cheeky really: It suggests that 'we all agree, don't you?'

And therein lies the nudge. By using the word agree, it’s implying that there is already mass support for this issue. Otherwise, why would you be asked to agree with it? We associate agreement with a positive effect, so it’s brilliantly worded in that sense.

The Yes campaign could’ve gone further of course. On the extreme end of the scale, someone might have suggested: Do you believe our beloved country ought to remain tied to a tyrannical, brutish England?

Someone else might’ve suggested the simple: Do you love your country? 

On the No side, their copywriters must’ve been proposing some similarly biased questions. Maybe something like: Could Scotland sustain itself as an independent country?

This puts doubt and worry into the reader’s mind – 2 things that should never usually be put into a call-to-action. But if you’re looking for that No vote, this nudge would work perfectly.

As it turned out, a supposedly balanced question has now been proposed. The neutral-sounding Should Scotland be an independent country: yes/no?

It’s a simpler, more refined question – altogether beiger. But the Yes and No copywriters must be frustrated to see their well-crafted copy nudges go to waste.