Skin color

Skin colour is probably the most well-known and at the same time, the most overrated anthropometric trait. In many societies it is seen as the most important factor to define race. However, scientifically it is just one of many anthropometric traits that contribute to defining an anthropological type. Caucasoids may show pale skin in Northern Europe and dark brown skin in South India. Negroids may show light brown skin in tropical forest populations and in South Africa, but black skin in dry savannahs. Mongoloids may show fair skin in North-East Asia and dark brown skin in Native American groups of the Sonora and the Andes. Because sun alters skin colour, it is usually measured below the armpits. There have been various attempts to sort different skin colours into categories. The most prominent historical concept is the 35 skin colours defined by Felix von Luschan. Similarly, Paul Broca defined 34 skin colours, Garson-Ried-Denicker 10 to 12. A scale used in modern dermatology is the scale of Thomas B. Fitzpatrick that uses six skin colour types. The types in humanphenotypes are usually grouped into six categories as well, which are illustrated below. The map shows regions where a specific skin colour is common in native populations. On an individual level, different skin colours may regularly appear in the black areas as well.

pale

fair

light brown

medium brown

dark brown

black

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Pale skin: Pale skin roughly corresponds to a Luschan scale of 1-5. It is mainly found in Northern Europeans. Only developed in regions with low solar radiation, because it offers little protection to sunburn. The climate that favours the development of pale skin the most is not the icy polar climate where the snow reflects sunlight during the summer. Instead, cloudy and cool temperate climate like that of the Faroe Islands favours it the most. Some studies indicate a development during the Neolithic in European farmers. In most pale-skinned individuals only a mild tanning can be achieved by exposure to the sun, but the skin easily burns and turns red. The maximum paleness is usually reached during the late winter months. Pale-skinned individuals often show freckles and are red or blonde haired, occasionally brown-black haired. Some historical and modern societies regard pale skin as an ideal, others try to reduce paleness through artificial tanning.

Fair skin: Fair skin roughly corresponds to a Luschan scale of 6-11. Fair skin is the typical skin tone of most Europeans excluding Mediterraneans. It sporadically occurs in Siberia (e.g. Evens, Negidals), North Africa, as well as parts of Asia and America, e.g. in Fuegians and Pacifids. The protection against solar radiation is relatively weak, and sunburn occurs easily, especially if the skin is untanned and in (sub)tropical regions. Typically developed in temperate climate. Was probably rarer during the Paleolithic and increased in frequency during the Neolithic in European farmers. During the summer months, the skin may reach a brown tone which offers greater protection to solar radiation. Fair-skinned individuals are often brown haired, sometimes blonde or black haired.

Light Brown skin: Light brown skin is probably the most frequent skin colour in the world. It roughly corresponds to a Luschan scale of 12-17. It is very common in European regions with subtropical climate, and most cold and temperate non-European regions. It is frequent in Mediterraneans, Turkic groups, Siberians, East Asians, Polynesians, and many Native Americans. In the latter groups, the light brown skin tone often shows a slight yellowish, sometimes reddish tendency. The protection against solar radiation is modest, it can burn easily in untanned individuals, especially in tropical regions. During the Paleolithic, it also dominated in European populations. During the summer months, the skin tans easily, reaching a darker brown which offers a good protection against solar radiation. Most individuals with light brown skin have brown or black hair and dark eyes.

Medium Brown skin: Medium brown skin is common in many subtropical and tropical regions of the world. It roughly corresponds to a Luschan scale of 18-23. Depending on the region, it may show an olive, yellowish, or copperish tone. Apart from Europe, it is frequent in certain populations of all continents. In Africa, many groups of the Sahara as well as Khoisans and a few forest populations show medium brown skin. It is widespread in South and South-East Asians, and many Native Americans who live in tropical or subtropical climate. The tropical Mongoloid groups have a thicker stratum corneum, which gives a yellowish tint. It protects better against solar radiation, thus the selective pressure to develop dark skin is reduced. In addition, these groups migrated relatively late to their current habitat. Medium brown skin shows a good protection against solar radiation. It can burn in untanned skin. Many early human groups probably possessed this skin tone.

Dark Brown skin: Dark brown skin, often erroneously referred to as "black", is the typical skin colour of most tropical regions. It roughly corresponds to a Luschan scale of 24-29. It is the major skin tone of Sub-Saharan Africans from savannahs, tropical forests, to South African deserts. It is equally common in the Saharan Toubou, South Indians, among Asian Negrito populations, and typical for most Aboriginal Australians. It also dominates in Melanesians. A few native Americans may also show this skin tone. Dark brown skin offers a good protection against strong solar radiation, at the same time studies show a higher vulnerability to severe cold and reduced production of vitamin D in dark winter months of cold regions. Sun burn is possible. Many early Homo sapiens probably possessed this skin tone.

Black skin: Black skin is sporadically found in tropical regions. It roughly corresponds to a Luschan scale of 30-36 and sometimes shows a blueish tint. It is relatively rare in the central tropics, where humid climate and many clouds offer some protection against the sun. Instead, it is found in dry savannahs, where the sun burns throughout the day. The most populous black-skinned group are the Nilotes of African savannahs, but it also occurs in several Sudanid groups, especially around Senegal, in Mountain Dama, and a few Bantu groups. Outside of Africa, Andamanese, some Melanesians (e.g. in the Western Solomons and Bougainville), a few North Australians, and South Indians may show black skin. Black skin offers the best protection again strong solar radiation, sunburn hardly occurs. The strong pigmentation often alters the colour of the lips and eye sclera as well.