MUCH of politics is about emotion.

Alex Salmond and the spinmeisters of the SNP have a very clear understanding of that. The party's emphatic victory at the last Holyrood elections was partly a tribute to the party's competence in government, but it was just as much about its ability to paint an upbeat picture of a sunny successful future for Scotland and make voters believe in it. It won people's votes by winning their hearts.

However, those running the Yes campaign for independence will have to do a lot more than that if they are to have any hope of winning the referendum, judging from today's report analysing the results of the 2011 British Social Attitudes Survey. Voters may follow their hearts in Scottish Parliament elections but when it comes to deciding the future status of Scotland in the autumn of 2014, there is much evidence that they will be more concerned about the pounds in their pockets than the songs in their hearts.

The SNP yesterday pointed to the fact that, while most polls put support for independence at around a third, in the 2011 survey of social attitudes in Scotland 43% supported the option "Scottish Parliament make all decisions" (though the question did not refer explicitly to independence). As the authors admit, this is something of a puzzle.

Nevertheless, drilling down into this very detailed survey suggests that, despite positive attitudes to independence when it comes to notions such as feelings of national pride, severe doubts remain about the future of the economy and that is likely to be the deciding factor. More than half of those surveyed believed independence would raise their tax bills and 46% said they were "worried" about Scotland becoming independent. The biggest challenge for the SNP is that more than half of those who voted for it last year seem to oppose Scotland leaving the Union. "It would appear that most people in Scotland have yet to be persuaded that it would bring significant material benefits," says the report, part-written by Professor John Curtice of Strathclyde University.

Though his conclusions are based on a year-old survey, there is little evidence from more recent polls that support for outright independence is growing, despite the relative popularity of the SNP Government. Is the SNP perhaps a victim of its own success, with home rule within the Union appearing more attractive to a naturally cautious electorate than outright independence? Women in particular seem harder to win over.

The same uncertainty over the economy is reflected in the call from senior business figures today for more clarity about the future tax regime of an independent Scotland. A poll of 200 senior managers for Ernst & Young entitled Grasping The Thistle reveals two-thirds of them doubt the feasibility of establishing a new tax regime quickly, cheaply and efficiently. And though, predictably, nearly half favoured lowering corporation tax, many are worried about the cost of a new tax system, given that many businesses are run on a UK-wide basis. The fact that a number of prominent Scottish businessmen have come out in favour of independence reflects genuine divisions of opinion about such matters.

There were disagreements yesterday about how to read the runes of such surveys with both the pro- and anti-independence camps able to put their own gloss on the results. Overall, the conclusion must be that while not dismissing the idea of independence, a majority of Scottish voters need a lot more assurance that they personally and the country as a whole would flourish better outside the UK.