The Caucasian race, sometimes called the Caucasoid race, is defined by the Compact Oxford English Dictionary of Current English as "relating to a broad division of humankind covering people from Europe, Western Asia, parts of the Indian Subcontinent and North Africa" or "white-skinned; of European origin" or "relating to the region of the Caucasus in SE Europe". The concept originated in attempts chiefly by 19th c. European thinkers to develop a method of racial classification. This typological method was discredited and the concept is not relied on in scientific work related to humans.
However, it survives along with the similar classification "white" in many sociological studies, most of which require respondents to choose their "race" from a list of terms. Some also allow "other" or "mixed". The idea is to use the self-selected classification (sometimes selected by the surveyor by appearance) for correlational studies, sometimes in conjunction with other sciences, especially medicine and public health. It is also retained with the corresponding terms Negroid and Mongoloid in a scientific sense in biological anthropology.
With the turn away from racial theory in the late 20th century, the term "Caucasian" as a racial classification fell into disuse in Europe. In Germany and Russia, the term "Europid" or "Europoid" is used. Some authorities in Europe, especially in Russia and nearby, use the term "Caucasian" exclusively to identify people who are from the Caucasus region or who speak the Caucasian languages.
One justification for the use of the term is linguistic. The consensus is that the Proto-Indo-European language's point of origin was probably in the Southern Caucuses or Anatolia and this language group was adopted by most of those with the assigned phenotype in prehistory.
In the United States, "Caucasian" has been mainly a distinction based on skin color with "white" or light complexion. Caucasians are also distinguished as a people who are, or whose ancestors were, "from Europe" .