Red hair

Red hair, also known as orange hair^{[citation needed]} or ginger hair, is a human hair color found in 1–2% of the world population, appearing with greater frequency (2–6%) among people of Northern or Northwestern European ancestry and lesser frequency in other populations. It is most common in individuals homozygous for a recessive allele on chromosome 16 that produces an altered version of the MC1R protein.^[1]

Red hair varies in hue from a deep burgundy or bright copper, or auburn, to burnt orange or red-orange to strawberry blond. Characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin, it is typically associated with fair skin color, lighter eye color, freckles, and sensitivity to ultraviolet light.^[2]

Cultural reactions to red hair have been varied. The term "redhead" has been in use since at least 1510,^[3] while the term "ginger" is sometimes used, especially in Britain and Ireland, to describe a person with red hair.

The origin of red hair can be traced to Central Asia, caused by a mutation in the MC1R gene.^[4][5]