Blame the prevalence of ginger hair among the Scottish people on genes and even the weather, says a new study.
A genetics research student Emily Pritchard, 26, revealed her insights in an article about her sister's red hair for a University of Edinburgh magazine.
She explained the love of ginger hair among the Scots through a formula - genetic mutation + bad weather = red heads.
And said that the formula "was speculation rather than scientific study, but it is plausible."
It has been observed that while redheads amount to 1-2 per cent of the European population, an estimated 8 per cent of Scots and Irish are ginger.
Although human beings probably evolved in Africa 1 million to 2 million years ago, red hair appeared only once they had settled in Europe, possibly as recently as 20,000 years ago.
Ms Pritchard's explanation of this trait is based on well-established scientific theory.
Its foundation is the premise that ginger hair is genetically less advantageous because redheads have fair skin and are more prone to sunburn and skin cancer - unhelpful characteristics in hunter-gatherer societies.
In large populations in sunny climates, the ginger strain would tend to die out.