James IV, King of Scots, never had to worry about elections. This freed him up to satisfy his voracious curiosity with strange experiments: according to one old tale, in 1493 he trapped two children, and a nurse who couldn’t talk, on Inchkeith Island in the Firth of Forth.

James hoped that the children, deprived of modern influences on their speech, would naturally return to the true, divine language. They supposedly came back speaking Hebrew; for Walter Scott, it was “more likely they would scream like their dumb nurse, or bleat like the sheep and goats on the island”.

Last week’s Scottish parliament election promised an equally profane revelation. With Reform UK’s arrival in Scottish politics, Kenny Farquharson predicted in the Times that election day “will be remembered as the day Scottish exceptionalism died”. Sheepish voters, dumbly following the rest of Britain, would finally espouse the “rightwing populist nativism” that had hitherto been halted at Hadrian’s Wall.

On the surface, the results do suggest a change in tone. Reform won 17 seats –only two more than the Scottish Greens – tying with Scottish Labour for second place. Its surge from nowhere to 16% of the vote is unprecedented at Holyrood, rivalled only by the SNP’s 13-point rise in 2011.

That is still a long way short of Reform’s projected UK-wide share of about 27%. It is only thanks to Scotland’s dual-vote electoral system that Reform can celebrate any real success, with all its seats coming from the regional list, elected by proportional representation. Its best constituency performance, using the first past the post system, was 34% in the fishing constituency of Banffshire and Buchan Coast, one of the few places in Scotland with a substantial pro-Brexit contingent. Even there, the SNP beat it to the seat by a few hundred votes.

Reform’s chief victims were the Conservatives, who sustained their worst ever result in Scotland. While polarisation over independence helped the Tories replace Labour as Holyrood’s main opposition for a decade from 2016, more than half of their hard-won 31 seats have now vanished. In fifth place, Toryism has been reduced to a few rural fiefdoms in the south and north-east.

The election was won, as usual, in Scotland’s postindustrial central belt, where a fifth of the country’s constituencies huddle around abandoned seams of coal. Places such as Bathgate, Falkirk, Hamilton and Motherwell, where political loyalties have been stretched thin across pockets of decline and renewal, seem to be fertile ground for Reform. The SNP lost between 7% and 15% of voters in most central belt seats, but survives thanks to the colossal heights from which it is falling; in not one of them did the party drop below a third of the vote.

In many central belt seats, Reform is now snapping at Labour’s heels. After losing most “Yes” voters to the SNP after the independence referendum, Labour made the working-class pessimism of “No” into a bulwark against further decline. Socially conservative, anti-independence voters who hated the Tories had nowhere else to go. Until now. Of the 15 seats where Reform won more than a fifth of the vote, 12 were classically postindustrial. In every single part of Scotland’s rustbelt, the hard right won more than 10%.

There are still reasons for centre-left optimism. Tory losses to the left as well as the right mean that at 29 seats, Holyrood’s rightwing cohort is slightly smaller (by two seats) than it was last election. The progressive bloc, with 100 seats between the SNP, Labour, Liberal Democrats and Greens, has been stable for a decade. In terms of daily governance, this parliamentary arithmetic matters far more than the “mandate” for an independence referendum that Westminster is all but certain to refuse.

Progressive Scotland’s radical wing saw its best ever Holyrood result, with 15 Green MSPs surpassing the seven Greens and six Scottish Socialists elected in 2003. “Left-populist” policies such as free bus travel and taxing the rich helped the Greens take regional seats in every part of Scotland, beating the SNP to first place in Glasgow Southside and Edinburgh Central, as well as regional seats in every part of Scotland.

Reduced to 58 seats – seven short of a majority – the SNP’s big tent is fraying at the edges, but it has recovered from a grim showing in 2024 thanks to the UK-level failures of its main opponents. John Swinney may now lean more heavily on the Lib Dems than the Greens to keep his incoming government in the centre ground.

While the right’s vote share at Holyrood is the largest it has ever been, at about 28%, it is nevertheless one of the worst rightwing performances in Europe. The SNP has benefited again from its distance from Westminster politics, but it should not underestimate Reform’s ability to do the same. Swinney has already pledged to lock Reform out of any policy negotiations, but he also needs to make a convincing argument about why it is not welcome.

There is a precedent for his approach at Inchkeith: shortly after James IV’s language experiment, the island became a colony for sufferers of “grandgore” (the old Scots name for syphilis). We should remember that the real purpose of Scotland’s mythical leftwing identity is not to make us feel better about ourselves, but to exile the right from the political community and limit its spread.

• Rory Scothorne is a historian and writer based in Edinburgh