RELEASE a poll on Scottish independence, and you are guaranteed two things: politicians for whom it is positive news will trumpet it, and those for whom it is negative will play it down or dismiss it.

The reaction to the latest Scottish Social Attitudes (SSA) survey findings has been no different. The SNP and other pro-independence groups are running out of superlatives to describe the conclusion that most Scots support independence and that that support now stands at its highest since the SSA began asking in 1999.

Conversely, unionist groups and politicians were quick last night to rubbish it. Alex Cole-Hamilton, leader of the Scottish Liberal Democrats, epitomised this tendency with his handwaving of The National’s coverage, characterising the SSA as a year-old poll in which independence was two points ahead.

Cole-Hamilton’s arithmetic is extremely dodgy here – independence is, in fact, 14 points ahead of the next best-supported option, devolution.

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More importantly, Unionists’ dismissal of the SSA is a classic case of burying one’s head in the sand – something they do at their peril.

The SSA is not just any poll. They recruit participants through random sampling instead of the panels most pollsters use. This is both more expensive and more time-consuming. But it also helps to avoid data skewed towards the more politically engaged and online – meaning the SSA’s data is more robust and reliably representative of the Scottish population than standard polling.

More importantly, the constitutional preference question the SSA asked is not the usual voting intention question we see in most polls. Instead, the SSA asks participants how Scotland should be governed, giving five options. Two of these are as an independent country (in or out of the European Union), two are within the UK but with a Scottish Parliament (with or without power over some taxes), and one is within the UK and without a Scottish Parliament.

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This means that support for independence in the SSA is not predictive of voting intention – the 2014 survey found 33% support for independence during a period when regular polls showed Yes at around 40% of the vote.

This is not a bug. It’s a feature. The SSA isn’t interested in what voters say they’d do in a hypothetical referendum tomorrow. It’s interested in their underlying attitudes, beliefs and preferences, which in turn drive behaviour.

This is why, far more than any poll showing Yes ahead, Unionist politicians should be concerned by the SSA. While voting intention can be unstable and highly responsive to events, underlying attitudes can be very “sticky”, taking a long time to change.

It has taken a lost referendum, Scotland being taken out of the European Union against its will, a pandemic in which Scots think Holyrood outperformed Westminster, and over a decade of highly unpopular Conservative governments for attitudes to shift to this point.

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It could take a similarly lengthy trend of positive developments for Scotland in the Union to reverse this shift towards independence.

As in 2014, many may prefer independence in an ideal world but might be put off by perceived risks in a future vote. However, the simple reality is that the cohort of Scots willing to make a go of it outwith the Union now make up a majority of the population – a much larger potential voting block than ahead of the 2014 referendum and has been since 2019.

There remains a great deal of unpredictability around whether, when, and under what circumstances another vote on Scotland’s constitutional arrangements might occur. But should it go ahead, the SSA makes clear that the independence movement will find itself in a more advantageous starting position than at any point since at least the beginning of the 21st century.

That itself justifies the independence movement’s ebullience. Those who want to keep the Union together, on the other hand, would do well to take this flashing warning light much more seriously.