Read enough about health and you will stumble upon some weird, difficult to explain correlations. The latest that I’ve found is what appears to be a lower risk of prostate cancer in men with red hair, according to the British Journal of Cancer:
Prostate cancer risk did not differ by eye colour or skin phototype. Men with naturally red hair were significantly less likely to develop prostate cancer (HR=0.46, 95% CI 0.24-0.89) than men with light brown hair (reference).
And they have no idea why. At least they’re honest, I prefer honesty over pretending to know the answer to something. Anyway, they suspect high vitamin D levels may be protecting redheads from cancer, since red hair and very light skin tend to go together, and light skin is better at absorbing the type of sun rays that stimulate vitamin D production. Unfortunately, this of course may mean that redheads are at a higher risk for skin cancer.
On the other hand, black men tend to have a significantly higher risk of prostate cancer. This may be due to a mixture of genetic and socio-economic factors.
Red hair is relatively uncommon, even in Europe. Among Europeans, it is estimated that about 4% have red hair while it is much more common in the British Isles and Ireland.
Redheads are often stereotyped as being hot-headed or passionate, though I do not know if there is any truth to this. Whatever the case may be, many influential people from history and a lot of celebrities are natural redheads – Famous Redheads Throughout History