Red hair

From Wikipedia, the free encyclopedia

Red hair (also referred to as auburn, ginger, or titian) is a hair color that varies from a deep red through to bright copper. It is characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin. People with red hair are often referred to as redheads.

Red is an uncommon hair color among humans; at most, two percent of the human race is redheaded.^[1] Red hair is found mainly in Northern and Western European populations, and their descendants, although it occurs in low frequencies throughout other parts of Europe, Asia and Africa. Red hair appears to be caused by a recessive gene on chromosome 16 which causes a mutation of the MC1R protein. It is associated with fair skin color, freckles, and sensitivity to ultraviolet light. Cultural reactions have varied from ridicule to admiration; a common stereotype is the “fiery-tempered redhead”.^{[citation needed]}

As well as in humans, red hair can be found in other mammalian species such as orangutans, squirrels, and highland cattle. Red hair or fur can be found in some breeds of dog and cat, and certain species of fox and deer.

Contents 1 Historical 2 Modern 3 Biochemistry and genetics 3.1 Genetics 3.2 Evolution 4 Medical implications 4.1 Bleeding and bruising 4.2 Melanoma 4.3 Sensitivity to pain 4.4 Associated pathologies 5 Culture 5.1 Beliefs about temperament 5.2 Negative attitudes towards redheads 5.3 Related beliefs, stories and traditions 5.4 Modern fiction 6 See also 7 Further reading 8 References 9 External links

[edit] Historical

Several accounts by Greek writers detail redheaded people. A fragment by the Greek poet Xenophanes describes the Thracians as blue-eyed and red haired. The Greek historian Herodotus described the "Budini", probably Udmurts and Permyak Finns located on the Volga in what is modern-day Russia, as being predominantly redheaded. The Greek historian Dio Cassius described Boudica, the famous Celtic queen of the Iceni, to: "be tall and terrifying in appearance ... a great mass of red hair ... over her shoulders".

The Roman Tacitus commented on the "red hair and large limbs of the inhabitants of Caledonia Scotland",^[2] which he linked with some red haired Gaulish tribes of Germanic and Belgic relation.

Red hair was also found in Asia, notably among the Tocharians who occupied the northern most province of what is modern-day China. The 2nd millennium BC caucasian Tarim mummies in China were found with red and blonde hair.^[3]

[edit] Modern

Today, red hair is most commonly found at the northern fringes of Europe. It is associated with those in Scotland, Ireland, and Wales, as well as in England, particularly Cornwall.

Scotland is the country with the highest proportion of redheads in the world. 13 percent of the Scottish population has red hair and approximately 40 percent carry the recessive, so-called "ginger gene".^[4]

Ireland has the second highest number of redheads worldwide; as many as 10 percent of the Irish population have ginger or strawberry blond hair. It is thought that up to 35 percent of the Irish population carries the recessive "ginger gene".

Red hair has a frequency of over 10 percent in Wales.^[5] In England, the county of Cornwall and the far north, near the Scottish border, also have significant proportions of redheads.

Red or reddish-tinged hair is also found in other European populations particularly in the Nordic and Baltic countries as well as parts of the Netherlands, Northern Germany and Russia.

In the United States, anywhere from two to six percent of the population is estimated to have red hair.^[1]

The Berber and Kabylie populations of northern Algeria have occasional redheads.^[6]

In Asia, darker or mixed tinges of red hair can be found sporadically from Northern India, Iran and Pakistan, all the way to Japan. Red hair can be found commonly amongst those of Iranian descent, such as the Pashtuns.^[7]

[edit] Biochemistry and genetics

The pigment pheomelanin gives red hair its distinctive color. Red hair has far more pheomelanin than other hair colors, but far less of the dark pigment eumelanin. Auburn hair has both pheomelanin and eumelanin.

The genetics of red hair, discovered in 1997, appears to be associated with the melanocortin-1 receptor, which is found on chromosome 16. Red hair is associated with fair skin color and sensitivity to ultraviolet light. The MC1R recessive gene, which gives people red hair and fair skin, is also associated with freckles, though it is not uncommon to see a redhead without freckles. Eighty percent of redheads have a MC1R gene variant,^[8] and the prevalence of these alleles is highest in Scotland and Ireland. The alleles that code for red hair occur close to the alleles that impact skin color, so it seems that the phenotypic expression for lighter skin and red hair are interrelated.

There is some indication that the uncommon pheomelanin/eumelanin ratios found in redheads may be correlated with some corresponding variations in the abundance of other hormones and neuropeptides, including epinephrine (adrenaline), dopamine, and oxytocin. Wolves which are bred to be tame have been found to acquire a progressively paler coat of fur as they become tamer and tamer through successive generations. The speculation is that the cell biology which produces epinephrine (adrenaline) needed for the high-energy fight-or-flight response is linked to the cell biology that governs the relative production of pheomelanin and eumelanin. This finding might explain why redheads are often characterized as having a distinct temperament compared to the rest of the population. This finding might also explain why redheads appear to be over-represented in breakthroughs in the cerebral arts. Socrates, Galileo, and Darwin were redheads, as were Vincent Van Gogh, Mark Twain, and JK Rowling. Redheads also appear to be over-represented in comedy, as well.^{[citation needed]}

[edit] Genetics

The genetics of red hair are now being uncovered, together with connections between red hair and melanoma, skin disorders in general, and different reactions to anaesthesia. There is evidence of genetic linkage of eye color with other hair colors, such as brown hair, although MC1R is not linked to eye color. The inheritance of red hair is close to what geneticists describe as an autosomal recessive mode of inheritance. This means that the parents of red haired children may carry the gene for red hair but not have red hair themselves.

There is also evidence that red hair may be an example of incomplete dominance. This means that when only one copy of the red hair allele is present, red hair may blend with the other hair color, resulting in different types of red hair including strawberry blond (red-blonde) and auburn (red-brown).

The alleles Arg151Cys, Arg160Trp, Asp294His, and Arg142His on MC1R are shown to be recessives for the red hair phenotype.^[9]

Also possibly related to red hair is the gene HCL2 (aka RHC, RHA) on chromosome 4.^[10][11]

[edit] Evolution

Red hair is the rarest type of natural hair color in humans and the reasons for its occurrence are unclear. The pale skin associated with red hair may be of advantage in far-northern climates where sunlight is scarce. Studies by Bodmer and Cavalli-Sforza (1976) hypothesized that lighter skin pigmentation prevents rickets in colder latitudes by encouraging higher levels of Vitamin D production and also allows the individual to retain heat better than someone with darker skin.^[12] Rees (2004) suggested that the vividness and rarity of red hair may lead to it becoming desirable in a partner and therefore it could become more common through sexual selection.^[13]

Harding et al (2000) proposed that red hair was not the result of positive selection but rather occurs due to a lack of negative selection. In Africa, for example, red hair is selected against because high levels of sun would be harmful towards fair skin. However, in Northern Europe this does not happen and so redheads come about through genetic drift.^[9]

Estimates on the original occurrence of the currently active gene for red hair vary from 20,000 to 100,000 years ago.^[14][15] Based on a 2001 Oxford University study, some commentators speculated that Neanderthals had red hair, and that some redheaded and freckled humans today share some genetic heritage with Neanderthals.^[16][17] Other researchers disagree,^[14] and the scientists who conducted the 2001 Oxford study have said that this is a misinterpretation of their findings.^[15]

[edit] Medical implications

[edit] Bleeding and bruising

There is little or no evidence to support the belief that redheads are more likely than non-redheads to haemorrhage or suffer other bleeding complications;^[18][19] however, one study found that redheads reported higher rates of bruising.^[19]

[edit] Melanoma

Melanin in the skin aids UV tolerance through suntanning, but a typical redhead lacks melanin and is more likely to get sunburn. Studies have shown that red hair alleles in MC1R effect increased freckling and decreased tanning ability.^[20] It has been found that Europeans that are heterozygous for red hair exhibit increased sensitivity to UV radiation.^[13]

Red hair and its relationship to UV sensitivity are of interest to many melanoma researchers. Sunshine can both be good and bad for a person's health and the different alleles on MC1R represent these adaptations. It also has been shown that individuals with pale skin are highly susceptible to a variety of skin cancers such as melanoma, basal cell carcinoma, and squamous cell carcinoma.^[21][22]

[edit] Sensitivity to pain

In people with red hair, the cells that produce skin and hair pigment have a dysfunctional MCR1. Researchers have found that this dysfunction triggers the release of more of the hormone that stimulates these cells, but this hormone also stimulates a brain receptor related to pain sensitivity.^[23][24]

Two studies have demonstrated that redheads have differential sensitivity to pain compared to non-redheads, but they differ as to the direction of the effect. One study found that redheads are more sensitive to thermal pain,^[25] while another study concluded that redheads are less sensitive to pain from electrical stimuli. It has also been found that mutated "redheaded" mice with non-functional MCR1 are less sensitive to pain from multiple modalities.^[26]

Researchers have found that redheads require greater amounts of anesthesia, but other research shows that women with naturally red hair require less of the painkiller pentazocine than do either women of other hair colors or men of any hair color. A study showed redheaded women had a greater analgesic response to that particular pain medication than men.^[27] A follow-up study by the same group showed that redheaded men and women (and mutant "redhead" mice) had a greater analgesic response to morphine-6-glucuronide.^[26]

[edit] Associated pathologies

Most red hair is caused by the MC1R gene and is non-pathological. However, in some cases red hair can be associated with disease or genetic disorder:

• In cases of severe malnutrition, normally dark human hair may turn red or blonde. The condition, part of a syndrome known as kwashiorkor, is a sign of critical starvation caused chiefly by protein deficiency, and is common during periods of famine.
• One variety of albinism (Type 3, aka rufous albinism), sometimes seen in Africans and inhabitants of New Guinea, results in red hair and red-colored skin.^[28]
• Red hair is found on people lacking pro-opiomelanocortin.^[28][29]

[edit] Culture

In various times and cultures, red hair has been prized, feared, and ridiculed.

Queen Elizabeth I of England was a redhead, and during the Elizabethan era in England, red hair was fashionable. This was also the case during the rule of redhead Oliver Cromwell^{[citation needed]}. In modern times, red hair is subject to fashion trends; celebrities such as Rita Hayworth, Shirley Manson or Gillian Anderson can boost sales of red hair dye.

Sometimes, red hair darkens as people get older, becoming a more brownish colour or losing some of its vividness. This leads some to associate red hair with youthfulness, a quality that is generally considered desirable. In several countries such as India, Iran, and Pakistan, henna is used on hair to give it a bright red appearance.^[30]

Many painters have exhibited a fascination with red hair. The colour "titian" takes its name from Titian, who often painted women with red hair. Other painters notable for their redheads include the Pre-Raphaelites,^[31] Edmund Leighton, Modigliani,^[32] Gustav Klimt^[33] and Sandro Botticelli, whose famous painting, The Birth of Venus, depicts the mythological goddess, Venus, as a redhead. Additionally, witches are frequently portrayed as redheads.

[edit] Beliefs about temperament

A common stereotype of redheads is that they have fiery tempers. In Anne of Green Gables, a character says of the redheaded heroine that "her temper matches her hair", while in The Catcher in the Rye, Holden Caulfield remarks that "People with red hair are supposed to get mad very easily, but Allie [his dead brother] never did, and he had very red hair."

During the early stages of modern medicine, red hair was thought to be a sign of a sanguine temperament.^[34] In the Indian medicinal practice of Ayurveda, redheads are seen as most likely to have a Pitta temperament.

Another belief is that redheads are highly-sexed; for example, Jonathan Swift satirizes redhead stereotypes in part four of Gulliver's Travels, "A Voyage to the Country of the Houyhnhnms," when he writes that: "It is observed that the red-haired of both sexes are more libidinous and mischievous than the rest, whom yet they much exceed in strength and activity." Swift goes on to write that: "...neither was the hair of this brute [a Yahoo] of a red color (which might have been some excuse for an appetite a little irregular) but black as a sloe..."

[edit] Negative attitudes towards redheads

During the Middle Ages in Southern and Central Europe, red was the colour of the devil and the redheads were said to be conceived during the forbidden period of women's menstruation.^{[citation needed]} Red hair was thought to be a mark of a beastly sexual desire and moral degeneration. According to Montague Summers, red hair and green eyes were thought to be the sign of a witch, a werewolf or a vampire in Eastern and Southern Europe ever since the Middle Ages. A savage red-haired man is portrayed in the fable by Grimm brothers (Der Eisenhans) as the spirit of the forest of iron. Theophilus Presbyter describes how the blood of a red-haired young man is necessary to create gold from copper, in a mixture with the ashes of a basilisk.^[35]

In modern-day UK and Ireland, despite being the places with the highest populations of redheads, the word "ginger" (often pronounced with two hard 'g's /'gɪ.ŋə/ to rhyme with 'ringer', as opposed to the standard pronunciation /'dʒɪn.dʒə/) is derogatorily used to describe red headed people. Redheads are also sometimes referred to as "carrot tops" or "fire crotches". This "gingerphobia"^[36] has been satirised on a number of TV shows. The British comedian Catherine Tate appeared as a red haired character in a running sketch of her series The Catherine Tate Show. The sketch saw fictional character Sandra Kemp, who was forced to seek solace in a refuge for ginger people because they had been ostracised from society. The pejorative use of the word "ginger", and related discrimination, was used to illustrate a point about racism and prejudice in the "Ginger Kids" episode of South Park. The British comedy Bo' Selecta! featured a spoof documentary which involved a caricature of red-haired "Simply Red" singer Mick Hucknall presenting a show in which celebrities (played by themselves) dyed their hair ginger for a day and went about daily life being insulted by people.

Films and television programmes typically portray school bullies as having red hair, based on the sterotype that redheads are more temperamental, and thus allowing the audience to identify the bully faster by their hair colour.

[edit] Related beliefs, stories and traditions

• The Biblical mark of Cain is thought by some to have been red hair^{[citation needed]}. Esau's entire body is supposed to have been covered with red hair. King David is also known for having red hair, based on the description of his physical appearance as "admoni", the Biblical Hebrew word normally interpreted to mean 'ruddy' and/or 'red-haired' (1 Samuel 16-17).
• Ancient Egyptians associated both red-haired humans and red-colored animals with the god Set, considering them to be favored by the powerful and temperamental deity. Several pharaohs associated with Set are described as being redheaded. The dynasties Tutmoses, Rameses and Mentuhotep included red (and orange) haired pharaohs.^{[citation needed]}
• Early artistic representations of Mary Magdalene usually depict her as having long flowing red hair, although a description of her hair color was never mentioned in the Bible, and it is possible the color is an effect caused by pigment degradation in the ancient paint. This tradition is used as a plot device in the book and movie The Da Vinci Code.
• According to British legend, King Arthur had long red hair^{[citation needed]} and would return to lead Britain through a time of hardship. Important British figures like Queen Elizabeth I and Sir Winston Churchill, both redheads, are said to be the fulfillment of this legend.^{[citation needed]}
• In Malaysia and Singapore, 'Ang Mo', meaning 'Red Hair', is slang for people of European ancestry of any hair color.
• In Australia, red haired people are often given the ironic nickname "Blue".
• There is a tradition amongst astrologers that the planet Mars is more likely to be rising above the eastern horizon at the time of the birth of a red haired person than for the population in general.^[37]
• The name of the ancient kingdom of Rus may have been derived from the local word for red hair. The name of Russia was subsequently adopted from the same root. See Etymology of Rus and derivatives (third bullet under Etymology) and Russia.
• According to popular history, the red-headed Norseman Erik the Red discovered Greenland.

[edit] Modern fiction

• The Sherlock Holmes story "The Red-Headed League" (1891) was a favourite of its author, Sir Arthur Conan Doyle, and included a sub-plot revolving around a pseudo-society restricted to redheads.
• Abraham Van Helsing is depicted as having red hair and blue eyes, rather ironic as some cultures marked such people as those who would become vampires.
• The 1840 comic play Der Talisman by Johann Nestroy is about prejudice against redheads.
• In The Illuminatus! Trilogy, green-eyed redheads are said to be the favorite cohorts of The Devil.
• In Still Life with Woodpecker by Tom Robbins, redheads are said to be children of the moon, thwarted by the sun and addicted to sex and sugar.
• Several children's book characters are depicted with red hair, including Pippi Longstocking and Little Orphan Annie. In the Harry Potter series, members of the Weasley family all have red hair, as does Harry's mother.
• In comics and science fiction, female characters with red hair (and often green eyes) are frequently portrayed as strong and "fiery" personalities. Examples are Mary-Jane Watson (wife of Spider-Man) and Jean Grey (founding X-Man), Poison Ivy (Batman villain), and Mara Jade Skywalker (from the Star Wars Expanded Universe).
• In Anne Rice's Vampire Chronicles, many redheads are mentioned. Among them are twin-red-haired witch/vampires Maharet and Mekare in Queen of the Damned, Maharet's fledgling Thorne in Blood and Gold, and her other fledgling and once-mortal blood descendant, Jesse Reeves (also introduced in Queen of the Damned). Later in the series, yet another red-haired vampire is introduced in Rice's novel Blackwood Farm (Mona Mayfair- her cousin, Fr. Kevin Mayfair is also a ginger.)
• In Robert A. Heinlein's Time Enough for Love, both Lazarus Long and the Wandering Jew are noted to have red hair, suggesting a (fictional) link between their hair and longevity.
• The South Park episode "Ginger Kids" showcased modern prejudice toward red haired people.

[edit] See also

• Melanocytes
• Melanin
• Keratinocytes
• Human skin colour
• Yuezhi or "Moon People" - Ancient Asian people linked to the Tocharians

[edit] Further reading

• Allen Sacharov. The Red Head Book (1985).
• Stephen Douglas. The Redhead Encyclopedia (1996).
• Tim Collins. The Ginger Survival Guide (2006).
• Uwe Ditz. Redheads (2000).
• Marion Roach. Roots of Desire: The Myth, Meaning and Sexual Power of Red Hair (2005).
• Cort Cass. The Redhead Handbook (2003).

[edit] References

[edit] External links

• OMIM entry on red hair
• The roots of red hair
• Red Hair genetics for non-specialists
• Melanocortin 1 receptor: What’s red got to do with it?
• The Melanocortin 1 Receptor (MC1R): More Than Just Red Hair
• Why is red hair with brown eyes so uncommon? MadSci Network
• A 2007 Sunday Times article, summarising the latest research on red hair in the British Isles.
• All About Redheads
• Red and Proud - a website about, for and by redheads
• Red Heads & Freckles Resource Center
• Distribution of hair and eye color and sex in 592 statistics students. from Snee, R. D. (1974).
• Painkiller Requirements May Be Less in Redheaded Women
• The Art of Being a Redhead - Gallery of 19th Century portraits of women with red hair
• Box NF, Wyeth JR, O'Gorman LE, Martin NG, Sturm RA. Characterization of melanocyte stimulating hormone receptor variant alleles in twins with red hair. Hum Mol Genet. 1997 October;6(11):1891–7.