The Caucasian race (also Caucasoid ^[1] or Europid)^[2] is a grouping of human beings historically regarded as a biological taxon, which, depending on which of the historical race classifications is used, has usually included ancient and modern populations from Europe, Western Asia, Central Asia, South Asia, North Africa, and the Horn of Africa.^[3][4]

First introduced in the 1780s by members of the Göttingen School of History,^[5] the term denoted one of three purported major races of humankind (Caucasoid, Mongoloid, Negroid).^[6] In biological anthropology, Caucasoid has been used as an umbrella term for phenotypically similar groups from these different regions, with a focus on skeletal anatomy, and especially cranial morphology, over skin tone.^[7] Ancient and modern "Caucasoid" populations were thus not exclusively "white," but ranged in complexion from white-skinned to dark brown.^[8]

Since the second half of the 20th century, physical anthropologists have moved away from a typological understanding of human biological diversity towards a genomic and population-based perspective, and have tended to understand race as a social classification of humans based on phenotype and ancestry as well as cultural factors, as the concept is also understood in the social sciences.^[9] Although Caucasian / Caucasoid and their counterparts Negroid and Mongoloid have been used less frequently as a biological classification in forensic anthropology (where it is sometimes used as a way to identify the ancestry of human remains based on interpretations of osteological measurements), the terms remain in use by some anthropologists.^[10]

In the United States, the root term Caucasian is often used, both colloquially and by the US Census Bureau, as a synonym for white. This usage is considered erroneous by anthropologists and other scientists, who note that it conflates an anthropologically valid category (Caucasoid) with the social construct of the "white race". The conflation of Caucasian with white is also demographically misleading since the category Caucasoid includes various populations, such as South Asians and Ethiopians, that are not considered white in a social sense.^[11]

The traditional anthropological term Caucasoid is a conflation of the demonym Caucasian and the Greek suffix eidos (meaning "form", "shape", "resemblance"), implying a resemblance to the native inhabitants of the Caucasus. In its usage as a racial category, it contrasts with the terms Negroid, Mongoloid, and Australoid.^[12]

The term Caucasian originally referred in a narrow sense to the native inhabitants of the Caucasus region.^[13] In his The Outline of History of Mankind (1785), the German philosopher Christoph Meiners first used the concept of a "Caucasian" (Kaukasischen) race in its wider racial sense.^[5][14][15]

Meiners acknowledged two races: the Caucasian or beautiful, and the Mongolian or ugly.

His Caucasian race encompassed all of the ancient and most of the modern native populations of Europe, the aboriginal inhabitants of West Asia (including the Phoenicians, Hebrews and Arabs), the autochthones of Northern Africa (Berbers, Egyptians, Abyssinians and neighboring groups), the Indians, and the ancient Guanches.^[16]

In his earlier racial typology, Meiners put forth that Caucasians had the "whitest, most blooming and most delicate skin".^[17] In a series of articles, Meiners boasts about the superiority of Germans among Europeans, and describes non-German Europeans' color as "dirty whites", in an unfavorable comparison with Germans.^[18] Such views were typical of early proto-scientific attempts at racial classification, where skin pigmentation was regarded as the main difference between races. This view was shared by the French naturalist Julien-Joseph Virey, who believed that the Caucasians were only the palest-skinned Europeans.^[19]

It was Johann Friedrich Blumenbach, a German professor of medicine and a member of the British Royal Society, and who came to be considered one of the founders of the discipline of anthropology, who gave the term a wider audience, by grounding it in the new methods of craniometry and Linnean taxonomy.^[20]

Blumenbach did not credit Meiners with his taxonomy, although his justification clearly points to Meiners' aesthetic viewpoint of Caucasus origins:^[21]

Blumenbach would later assert that of the various Caucasian varieties, the Northern European type (encompassing the present-day United Kingdom, France and Scandinavia) represented the perfect form.^[23]

In contrast to Meiners, however, Blumenbach was a monogenist – he considered all humans to have a shared origin and to be a single species.

Blumenbach, like Meiners, did rank his Caucasian grouping higher than other groups in terms of mental faculties or potential for achievement.^[20]

In various editions of On the Natural Variety of Mankind, Blumenbach expanded on Meiners' popular idea and defined five human races based on color, using popular racial terms of his day, justified with scientific terminology, cranial measurements, and facial features. He established Caucasian as the "white race", Mongoloid as the "yellow race", Malayan as the "brown race", Ethiopian as the "black race", and American as the "red race".^[24] In the 3rd edition of his On the Natural Variety of Mankind, Blumenbach moved skin tone to second-tier importance after noticing that poorer European people (such as peasants) whom he observed generally worked outside, often became darker skinned ("browner") through sun exposure.^[25]%2C%203rd%20ed.%20%281795]]%2C%203rd%20ed.%20%281795]]%2C%203rd%20ed.%20%281795]]%2C%203rd%20ed.%20%281795]]%2C%203rd%20ed.%20%281795]]%2C%203rd%20ed.%20%281795]]%2C%203rd%20ed.%20%281795]]%2C%203rd%20ed.%20%281795]]*

Following Meiners, Blumenbach described the Caucasian race as consisting of the native inhabitants of Europe, West Asia, the Indian peninsula, and North Africa, including toward the south the Moors, Abyssinians and adjacent groups.

His idealized Caucasian variety was distinguished by a white complexion, with rosy cheeks; brown or chestnut-colored hair; a subglobular head; an oval and straight face, with moderately defined parts; a smooth forehead; a narrow nose, often slightly hooked; and a small mouth.

However, pragmatically, Blumenbach acknowledged that skin color of the Caucasian variety naturally ranged from white to dark brown tones.^[8]

There was never any consensus among the proponents of the concept the existence of a "Caucasoid race" with regard to how it would be delineated from other proposed groups such as the proposed Mongoloid race. Carleton S. Coon (1939) included the populations native to all of Central and Northern Asia, including the Ainu people, under the Caucasoid label. However, many scientists maintained the racial categorizations of color established by Meiners' and Blumenbach's works, along with many other early steps of anthropology, well into the late 19th and mid-to-late 20th centuries, increasingly used to justify political policies, such as segregation and immigration restrictions, and other opinions based in prejudice. For example, Thomas Henry Huxley (1870) classified all populations of Asian nations as Mongoloid. Lothrop Stoddard (1920) in turn classified as "brown" most of the populations of the Middle East, North Africa, the Horn of Africa, Central Asia and South Asia. He counted as "white" only European peoples and their descendants, as well as a few populations in areas adjacent to or opposite southern Europe, in parts of Anatolia and parts of the Rif and Atlas mountains.

In 1939 Coon argued that the Caucasian race had originated through admixture between Homo neanderthalensis and Homo sapiens of the "Mediterranean type" which he considered to be distinct from Caucasians, rather than a subtype of it as others had done.^[28] While Blumenbach had erroneously thought that light skin color was ancestral to all humans and the dark skin of southern populations was due to sun, Coon thought that Caucasians had lost their original pigmentation as they moved North.^[28] Coon used the term "Caucasoid" and "White race" synonymously.^[29]

In 1962, Coon published The Origin of Races, wherein he proposed a polygenist view, that human races had evolved separately from local varieties of Homo erectus. Dividing humans into five main races, and argued that each evolved in parallel but at different rates, so that some races had reached higher levels of evolution than others.^[9] He argued that the Caucasoid race had evolved 200,000 years prior to the "Congoid race", and hence represented a higher evolutionary stage.^[30]

The dermis is thinner in whites than in other races; the exposed skin is vulnerable to sunburn because of the lower amount of melanin in the skin than in other races.^[31] These traits cause problems in warm climates, but the nearly transparent skin allows more sunlight to reach the inner layers of the epidermis, thereby increasing Vitamin D production far above the level found in other racial groups. A study of skin cultured from the hip region of Europeans and Africans living in Nigeria showed that European skins allow penetration of between 3 and 4 times as much UV radiation incident upon the skin.^[32]

Drawing from Petrus Camper's theory of facial angle, Blumenbach and Cuvier classified races, through their skull collections based on their cranial features and anthropometric measurements. Caucasoid traits were recognised as: thin nasal aperture ("nose narrow"), a small mouth, facial angle of 100°–90°, and orthognathism, exemplified by what Blumenbach saw in most ancient Greek crania and statues.^[33][34] Later anthropologists of the 19th and early 20th century such as Pritchard, Pickering, Broca, Topinard, Morton, Peschel, Seligman, Bean, Ripley, Haddon and Dixon came to recognize other Caucasoid morphological features, such as prominent supraorbital ridges and a sharp nasal sill.^[35] Many anthropologists in the 20th century used the term "Caucasoid" in their literature, such as Boyd, Gates, Coon, Cole, Brues and Krantz replacing the earlier term "Caucasian" as it had fallen out of usage.^[36]

Caucasoids (including Middle Eastern and South Asian peoples) have small teeth,^[37] with the maxillary lateral incisors often shrunken in size or replaced with peg laterals. According to George W. Gill and other modern forensic anthropologists, physical traits of Caucasoid crania can be distinguished from those of the people from Mongoloid and Negroid racial groups based on the shapes of specific diagnostic anatomical features. They assert that they can identify a Caucasoid skull with an accuracy of up to 95%.^{[38][39][40][41][42]} However, Alan H. Goodman cautions that this precision estimate is often based on methodologies using subsets of samples. He also argues that scientists have a professional and ethical duty to avoid such biological analyses since they could potentially have sociopolitical effects.^[43]

Variation in craniofacial form between humans has been found to be largely due to differing patterns of biological inheritance.

Modern cross-analysis of osteological variables and genome-wide SNPs has identified specific genes, which control this craniofacial development. Of these genes, DCHS2, RUNX2, GLI3, PAX1 and PAX3 were found to determine nasal morphology, whereas EDAR impacts chin protrusion and facial hair, both of which have been recently selected in Caucasians^[44][45]

The European mt-DNA Haplogroup J has been speculated to provide greater heat production upon exposure to cold than other haplogroups prevalent in the area.^[46] The mitochondrial uncoupling mechanism sets the ratio of body heat produced per calorie of food consumed, with Haplogroup J thereby increasing metabolism and warming the body.

In the 19th century Meyers Konversations-Lexikon (1885–90), Caucasoid was one of the three great races of humankind, alongside Mongoloid and Negroid. The taxon was taken to consist of a number of subtypes. The Caucasoid peoples were usually divided into three groups on ethnolinguistic grounds, termed Aryan (Indo-European), Semitic (Semitic languages), and Hamitic (Hamitic languages i.e. Berber-Cushitic-Egyptian).^[47]

19th century classifications of the peoples of India considered the Dravidians of non-Caucasoid stock as Australoid or a separate Dravida race, and assumed a gradient of miscegenation of high-caste Caucasoid Aryans and indigenous Dravidians. Carleton S. Coon in his 1939 book The Races of Europe, described the Veddoid race as "possess[ing] an obvious relationship with the aborigines of Australia, and possibly a less patent one with the Negritos" and as "the most important element in the Dravidian-speaking population of southern India".^[48] In his later The Living Races of Man (1965), Coon considerably amended his views, acknowledging that "India is the easternmost outpost of the Caucasoid racial region". However, he still recognized an Australoid substrate throughout the subcontinent, writing that "the earliest peoples who have left recognizable survivors were both Caucasoid and Australoid food gatherers. Some of the survivors are largely Caucasoid; others are largely Australoid."^[49] Sinhalese (Indo Aryan) population of Sri Lanka who were marked as uncertain in his first study due to lack of details were also reidentified as a Predominantly Mediterranean Caucasian race who are descending from early Northern Indian Indo Aryan settlers of the Island.

According to a large craniometric study (Raghavan and Bulbeck et al. 2013) the native populations of South Asia (India and Sri Lanka) are a Caucasoid group. Both southern and northern groups are most similar to each other and have generally closer affinities to various "Caucasoid" groups. The study further showed that the native South Asians (including the Vedda) form a distinct group and are not related to the "Australoid" group.^[50]

There was no universal consensus of the validity of the "Caucasoid" grouping within those who attempted to categorize human variation.

Thomas Henry Huxley in 1870 wrote that the "absurd denomination of 'Caucasian'" was in fact a conflation of his Xanthochroi (Nordic) and Melanochroi (Mediterranean) types.^[51]

Historically, the racial classification of the Turkic peoples was sometimes given as "Turanid". Turanid racial type or "minor race", subtype of the Europid (Caucasian) race with Mongoloid admixtures, situated at the boundary of the distribution of the Mongoloid and Europid "great races".^[52][53]

The Jōmon people of ancient Japan as well as the modern Ainu people are classified as Caucasoid by some anthropologists. Anthropologists like Jantz and Owsley (1997) consider the Ainu as Caucasoid subgroup.^[54] Arnold Henry Savage Landor described the Ainu as having deep-set eyes and an eye shape typical of Europeans, with a large and prominent browridge, large ears, hairy and prone to baldness, slightly hook nose with large and broad nostrils, prominent cheek-bones and a medium mouth.^[55]

Although Brace (1990) rejected a Caucasoid origin for the Jomon people and said that the Jōmon share many physical characteristics with Caucasians but are a separate genetic stock, a craniometric study by Brace et al. 2001 suggests not only morphological affinities to Caucasoids, but also possible genetic ties at one time (Pleistocene). The study results show a closer morphological relation between Ainu (including other Jōmon remnants) and West Asians rather than between Ainu and East Asians. The study concluded that the Ainu can be described as "Eurasians".^[56]

Hideo Matsumoto (2009) concluded that populations in India and nearby regions are basically Caucasoid while some have a minor Mongoloid admixture. Similarly Iranian peoples in Central Asia, such as Tajiks in Uzbekistan and Tajiks of Xinjiang are basically Caucasoid with a minor Mongoloid admixture.^[57]

The postulated subraces vary depending on the author, including but not limited to Mediterranean, Atlantid, Nordic, East Baltic, Alpine, Dinaric, Turanid, Armenoid, Iranid, Indid, Arabid, and Hamitic.^[58]

H. G. Wells argued that across Europe, North Africa, the Horn of Africa, West Asia, Central Asia and South Asia, a Caucasian physical stock existed. He divided this racial element into two main groups: a shorter and darker Mediterranean or Iberian race and a taller and lighter Nordic race. Wells asserted that Semitic and Hamitic populations were mainly of Mediterranean type, and Aryan populations were originally of Nordic type. He regarded the Basques as descendants of early Mediterranean peoples, who inhabited western Europe before the arrival of Aryan Celts from the direction of central Europe.^[59]

Among the earliest anatomically modern human settlements established in Europe were Kostenki-Borshchevo, Voronezh Oblast in southwestern Russia. DNA sequencing of a 37,000-year-old male skeleton from the area, Kostenki XIV or Markina Gora, indicates that these early settlers possessed a similar genetic makeup as modern Europeans, but had dark skin and dark eyes. They also possessed slightly more Neanderthal genes than modern populations in Europe and Asia due to interbreeding with Neanderthals over 45,000 years ago.^[60] In a study of Cro-Magnon crania, Jantz and Owsley (2003) have noted that these "Upper Paleolithic crania are, for the most part, larger and more generalized versions of recent Europeans."^[61]

William Howells (1997) has argued that Cro-Magnons were Caucasoid based on their cranial traits:

Carleton Coon (1962) argued that Caucasoid traits emerged prior to the Cro-Magnons, and were present in the Skhul and Qafzeh hominids.^[63] However, these fossils and the Predmost specimen were held to be Neanderthaloid derivatives because they possessed short cervical vertebrae, lower and narrower pelves, and had some Neanderthal skull traits. Coon further asserted that the Caucasoid race was of dual origin, consisting of early dolichocephalic (e.g. Galley Hill, Combe-Capelle, Téviec) and Neolithic Mediterranean Homo sapiens (e.g. Muge, Long Barrow, Corded), as well as Neanderthal-influenced brachycephalic Homo sapiens dating to the Mesolithic and Neolithic (e.g. Afalou, Hvellinge, Fjelkinge).^[3]

More recent osteological analysis of Cro-Magnon fossils indicates that they had larger skulls than modern populations, and possessed a dolichocephalic (long-head) and low cranium, with a wide face. It also suggests that some Cro-Magnons may have had brown skin.^[65] The very light skin tone found in modern Northern Europeans is a relatively recent phenomenon.^[66] It may have appeared in the European line as recently as 6 to 12 thousand years ago, indicating that Cro-Magnons had brown skin.^[67]

According to geneticist David Reich, based on ancient human genomes that his laboratory sequenced in 2016, ancient West Eurasians descend from a mixture of as few as four ancestral components related to the Eastern Hunter Gatherers (EHG), the Neolithic Iran, the Neolithic Levant and Natufians, and the Western Hunter Gatherers (WHG):^[68] As one editorial opinion expressed it:

A recent genetic study published in the "*European Journal of Human Genetics"*in Nature (2019) showed that populations generally included to the Caucasoid gouping, such as West Asians (Arabs), Europeans, Northern Africans and South Asians, are closely related to each other and can be distinguished from Mongoloid or Negroid populations.^[70]

In the United States, the term "Caucasoid" is used in disciplines such as craniometry, epidemiology, forensic medicine, forensic anthropology, and forensic archaeology.

It is also associated with notions of racial typology.

Besides its use in anthropology and related fields, the term "Caucasian" has often been used in the United States in a different, social context to describe a group commonly called "white people".^[71] "White" also appears as a self-reporting entry in the U.S. Census.^[72] Naturalization as a United States citizen was restricted to "free white persons" by the Naturalization Act of 1790, and later extended to other resident populations by the Naturalization Act of 1870, Indian Citizenship Act of 1924 and Immigration and Nationality Act of 1952. The Supreme Court in United States v. Bhagat Singh Thind (1923) decided that Asian Indians were ineligible for citizenship because, though deemed "Caucasian" anthropologically, they were not white like European descendants since most laypeople did not consider them to be "white" people. This represented a change from the Supreme Court's earlier opinion in Ozawa v. United States, in which it had expressly approved of two lower court cases holding "high caste Hindus" to be "free white persons" within the meaning of the naturalization act. Government lawyers later recognized that the Supreme Court had "withdrawn" this approval in Thind.^[73] In 1946, the U.S. Congress passed a new law establishing a small immigration quota for Indians, which also permitted them to become citizens. Major changes to immigration law, however, only later came in 1965, when many earlier racial restrictions on immigration were lifted.^[74] This resulted in confusion about whether American Hispanics are included as "white", as the term Hispanic originally applied to Spanish heritage but has since expanded to include all people with origins in Spanish speaking countries. In other countries, the term Hispanic is not nearly as associated with race, but with the Spanish language and cultural affiliation.

The United States National Library of Medicine often used the term "Caucasian" as a race in the past. However, it later discontinued such usage in favor of the more narrow geographical term European, which traditionally only applied to a subset of Caucasoids.^[75]