The skiers share a common ancestor high up in the family tree. Jöns Matinpoika Niemi, from Muoni in Finnish Lapland, can be traced to the 1600s.
"About all these skiers, you could say that they are descendants of the Meänkieli speaking population on both sides of the Tornio River," says genealogist Esko Orajärvi.
Five of the skiers have won Olympic gold, and most recently William Poromaa won world championship bronze.
Orajärvi does not believe that the common heritage has been decisive for success. But on the other hand, the culture in the north encourages skiing, he says.
Among Swedish skiers, Charlotte Kalla, Ida Ingemarsdotter, and William Poromaa share roots with each other, as well as Finnish skiers Eero Mäntyranta, Pertti Teurajärvi, Mona-Liisa Nousiainen and Sami Jauhojärvi.