Indeed, the trend uncovered by the government-funded Scottish Household Survey does need treating with some caution – the relevant survey question has been amended on more than one occasion, and that might well account for at least some of the change.
Still, the Scottish Social Attitudes survey, which has ascertained national identity on a consistent basis every year, also suggests that willingness to claim a Scottish identity is some five points lower now than a decade ago, when adherence to a Scottish identity appears to have been at an all-time high.
But will it matter anyway whether people feel Scottish or British, when eventually they get the chance to vote on Scotland’s constitutional future?
In truth the answer is yes and no. Few of those who do not primarily regard themselves as Scottish back independence – but, equally, feeling intensely Scottish by no means guarantees a wish to leave the Union.
According to the Scottish Social Attitudes survey, only 7 per cent of those who, when asked to choose a single identity, say they are British currently back independence. Despite some Nationalist attempts to suggest that independence and Britishness could go together, those with a strong sense of British identity are in fact more or less unanimously unionist. There are just not very many of them.
In contrast, 36 per cent of those who say they are Scottish back independence. However, many of those who say they are primarily Scottish also feel at least a little bit British as well.
Scottish and Britishness do often go together, even if independence and Britishness do not. It is only among the three in ten or so who not only say they are Scottish but who also deny they are British that there is majority support for independence – 53 per cent. But, of course, this means that even those who feel most fervently Scottish are divided down the middle on the constitutional issue.
The key challenge facing Mr Salmond is not to make Scots feel more Scottish. Rather, it is to persuade the many Scots who already have a distinctive sense of identity that independence makes practical as well as emotional sense.
• John Curtice is professor of politics at Strathclyde University.