This article deals with races defined craniofacially (based on skull measurements) and not by typology (physical type) or genetic distance. Races categorized using alternative methods yield different groups, making them non-concordant.^[1]

Craniofacial anthropometry is a technique used in physical anthropology comprising precise and systematic measurement of the bones of the human skull. Among its more important applications are: forensics, facial reconstruction, and paleoanthropology. The field of phylogeography, on the other hand, once relied heavily on this technique but no longer does so.^[2] Craniofacial anthropometry is a sub-field of Craniometry, which see for more detail and history.

History

Main article: Race (historical definitions)

The historical development of craniofacial anthropometry started when anthropologists first measured human skulls as a way to categorize race. The beginning physical anthropologists used a holistic method where they examined multiple observable physical characteristics to determine race. This holistic approach was not "craniofacial anthropometry" but a typological method. As anthropologists gained access to methods of skull measure, they developed racial classification based off skull shape. The observable craniofacial skeletal differences ranged from breadth of nasal aperture, nasal root height, head shape e.g. mesocephalic, brachycephalic and doliocephalic, sagittal crest appearance, jaw thickness, browridge size, forehead slope, etc., but did not involve soft tissue differences such as nasal shape, eye color, skin color, lip shape, and hair type. Using a strictly skull based categorization method, these anthropologists organized three to four racial groups. Caucasoids were characterized by a doliocephalic shape, with receded zygomas, large browridge and a narrow nasal aperture. Secondly, Negroids were characterized by a mesocephalic head shape, with receded zygomas and wide nasal aperture. Third, Mongoloids were characterized as a brachycephalic head shape, absent browridges, small nasal aperture, and projecting zygomas. Additionally, Australoids whose craniofacial type fell between Negroids and Caucasoids was added. With the addition of this category, Thomas Huxley considered India to fall in this group's craniofacial measurements.^[3]

In forensic anthropology

Main article: Forensic anthropology

The adjective "forensic" refers to the application of this subfield of science to a court of law. Forensic anthropologists study the human skeleton in a legal setting. A forensic anthropologist can assist in the identification of a decedent through various skeletal analyses that produce a "biological profile". One part to a biological profile is a person's racial/ancestral affinity.

Caucasians are generalized to have the lowest degree of projection of the alveolar ridge bones which contain the teeth, a notable size prominence of the cranium and forehead region, and a narrow, "silled" nasal aperture. Black traits are generalized to include a broader, more rounded nasal cavity; lower facial (prognathism); and a dolichocephalic skull (proportionally longer from front to back). Individuals of Asian decent can sometimes be characterized, by relatively no prognathism, complex sutures, and a rounded cranium. It is important to note that many of these characteristics only have a higher frequency among particular races and the presence or absence of one or more does not automatically classify an individual into a racial group. Forensic Anthropologist utilize the Fordisc program to help in the interpretation of craniofacial measurements in regards to ancestry/race determination.

In medicine

Surgeons employ the methods of craniofacial anthropometry in order to reconstruct a patient's face, when necessary, to fit within the limits of what society expects .

In paleoanthropology

Paleoanthropologists use craniofacial anthropometry in the study of fossilized hominid bones in order to identify the species. Specimens of Homo erectus and athletic specimens of Homo sapiens, for example, are virtually identical from the neck down but their skulls can easily be told apart.

In phylogeography

Phylogeography (see main article) is the science of identifying and tracking major long-distance migrations that bands of humans undertook, especially in prehistoric times. For a detailed account of Human migrations see that article. Linguistics can follow the movement of languages and archaeology can follow the movement of artifact styles, but neither can tell whether a culture's spread was due to a source population's physically migrating or to a destination population's simply copying the technology and learning the language. Craniofacial anthropometry helped resolve this because a people's physiognomy does not change rapidly due to mere migration.

Racial determination example

That craniofacial anthropometry is not as replicable as other ways of tracking human variation makes its findings difficult to explain. Here is a trivial example: imagine that you are handed a U.S. skull and asked to determine whether the person was White, Black, or Asian (that is, European-American, African-American, or Asian-American). Place the skull face down on a tabletop. Now try to rock it from side to side. If it fails to rock, but instead sits high on its cheekbones, with a face too flat to let the nose portion touch the table, then the chances are that it is of east Asian ancestry. If it rocks from side to side because the midline of the face protrudes past the cheekbones like the bow of a boat, then it is probably of either African or European ancestry. Now stand the skull upright so that it rests on the neck opening. If the face slopes down and forward because the mouth protrudes farther forward than the forehead, then it is likely of west African ancestry. If the face is vertical, it is probably of European ancestry. In practice, many other tests are necessary in order to hazard a determination but, in the end, it works because there are consistent differences among U.S. endogamous groups. A skull that matches the group of features associated with African-American ancestry is called "Negroid." Skulls with traits suggesting European and Asian ancestry are called, respectively "Caucasoid" and "Mongoloid."

Challenges

Although the categorization of a skull is clearly given arbitrary parameters, it will not locate the owners geographic ancestry concretely all the time. While one's perception of an individual's race can be affected by cultural aspects, the "race" of his skull is less ambiguous. As Dr. Stan Rhine put it, "...it is clear that race does mean different things to different people. In the context of forensic anthropology, the term race is unambiguous."^[4] Although their craniofacial race based on skull indices is unambiguous, it will not pin point their geographic origins accurately all the time due to variation in skulls within a geographic region.

While this method produces useful results for the population of the United States, it is likely that it would not be reliable for populations from other countries^[5] or historical periods.^[6] This is due to the fact that the United States has traditionally had groups whose ancestries came from geographically distant locations, and which have generally remained endogamous in this country, for social reasons. As more immigrants from in between regions and as Americans become more racially mixed, such craniofacial identification is problematic.

Classification by craniofacial anthropometry does not necessarily coincide with genetic ancestry or social self-identification. For example, about one-third of so-called "White" Americans have detectable African DNA markers.^[7] And about five percent of so-called "Black" Americans have no detectable "Negroid" traits at all, neither craniofacial nor in their DNA.^[8] In short, given three Americans, one who self-identifies and is socially accepted as U.S. White, another one who self-identifies and is socially accepted as U.S. Black, and one who self-identifies and is socially accepted as U.S. Hispanic, and given that they have precisely the same Afro-European mix of ancestries (one "mulatto" grandparent), there is quite literally no objective test that will identify their U.S. endogamous group membership without an interview.^[9] In practice, the application of such forensic criteria ultimately comes down to whether the skull "looks Negroid," "Caucasoid," or "Mongoloid" in the eye of each U.S. forensic practitioner.

Footnotes

See also

• Race (historical definitions)
• Craniometry
• Eigenface