What percentage of people are natural redheads?

Natural red hair occurs in about 1 to 2% of people worldwide, making it the rarest hair colour. It is most common in Scotland and Ireland, where figures of roughly 10 to 13% are often quoted, though these rest on small surveys rather than a national count. Red hair is usually caused by two copies of variants in the MC1R gene, so both parents must carry one.

Source: Valverde et al. (1995), Nature Genetics; Rees (2003), Annual Review of Genetics