He made that claim in his 2016 memoir Hillbilly Elegy, a bestseller which was subsequently turned into an Oscar-nominated film starring Glenn Close and Amy Adams.
The book describes a childhood spent surrounded by poverty and substance abuse in Appalachia, the broad mountainous region which extends across the eastern USA from Canada to the Deep South.
It’s estimated that about 90% of the area’s early European immigrants came in the 17th Century from the lands which stretch along both sides of the Scottish-English border.
These included Ayrshire, Galloway, Dumfriesshire and the areas now known as the Scottish Borders. Vance claims his ancestors were from Galloway and were part of this migration.
The terms Scots-Irish, Scotch-Irish and Ulster-Scots relate to people who left Scotland, settled as part of the Ulster plantation and then moved on to North America.
Appalachia today includes pockets of extreme poverty and its inhabitants are often offensively depicted as “hillbillies” – simple, unsophisticated and poor.
Vance’s memoir is an attempt to reclaim that tradition. He writes: “I may be white, but I do not identify with the WASPs (White Anglo-Saxon Protestant) of the Northeast.
“Instead, I identify with the millions of working-class white Americans of Scots-Irish descent who have no college degree.
“To these folks, poverty is the family tradition… Americans call them hillbillies, rednecks, or white trash. I call them neighbours, friends and family.”
The book sets out Vance’s developing political ideas as it charts his move towards conservatism.
And though he was at the time a critic of Donald Trump, the book explains why poor rural voters in places like Appalachia were becoming attracted to the Maga movement.