REDHEADED GENES IN SCOTLAND & IRELAND

Red is the rarest hair color in the world: less than 4% of world's population has naturally red hair. Scotland and Ireland have an unusually high incidence of redheadedness: it is reported* that Scotland currently at 11 to 13%, and Ireland at 10%. By contrast, most northern European populations carry about 2%. The rest of the world: 1%. Sweden, curiously, has almost no redheads at all.

Scientists agree that red hair is more common among those with genetic roots in northwestern Europe, especially Ireland and Scotland (and by extension, Argentina, and Australia—via immigration and penal colonies). This means that more Celtic Scottish (vs. Lowlander) and Irish people carry redheaded genes to produce all those redheaded offsprings. Irish people carry the highest ratio of red-haired gene (and its variations) in the world.