The cephalic index or cranial index is a number obtained by taking the maximum width ( biparietal diameter or BPD, side to side) of the head of an

organism An organism is any life, living thing that functions as an individual. Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have be ...

, multiplying it by 100 and then dividing it by their maximum length ( occipitofrontal diameter or OFD, front to back). The index was once used to categorize human beings in the first half of the 20th century, but today it is used to categorize dogs and cats.

Historic use in anthropology

Early anthropology

The cephalic index was used by anthropologists in the early 20th century as a tool to categorize human populations. It was used to describe an individual's appearance and for estimating the age of

fetus A fetus or foetus (; : fetuses, foetuses, rarely feti or foeti) is the unborn offspring of a viviparous animal that develops from an embryo. Following the embryonic development, embryonic stage, the fetal stage of development takes place. Pren ...

es for legal and obstetrical reasons. The cephalic index was defined by Swedish professor of

anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

Anders Retzius (1796–1860) and first used in physical anthropology to classify ancient human remains found in Europe. The theory became closely associated with the development of racial anthropology in the 19th and early 20th centuries, when historians attempted to use ancient remains to model population movements in terms of racial categories. American anthropologist Carleton S. Coon also used the index in the 1960s, by which time it had been largely discredited. PSM V59 D404 Cephalic indexes of skull shapes

PSM V59 D404 Cephalic indexes of skull shapes

In the cephalic index model, human beings were characterized by having either a dolichocephalic (long-headed), mesaticephalic (moderate-headed), or brachycephalic (short-headed) cephalic index or cranial index. Otmaa1917 1-1-

Indices

Cephalic indices are grouped as in the following table: Technically, the measured factors are defined as the maximum width of the bones that surround the head above the supramastoid crest (behind the cheekbones), and the maximum length from the most easily noticed part of the glabella (between the eyebrows) to the most easily noticed point on the back part of the head.

Controversy

The usefulness of the cephalic index was questioned by the Italian anthropologist

Giuseppe Sergi Giuseppe Sergi (March 20, 1841 – October 17, 1936) was an Italian anthropologist of the early twentieth century, best known for his opposition to Nordicism in his books on the racial identity of Mediterranean peoples. He rejected existing ra ...

, who argued that cranial morphology provided a better means to model racial ancestry. Also, Franz Boas studied the children of immigrants to the United States in 1910 to 1912, noting that the children's cephalic index differed significantly from their parents', implying that local environmental conditions had a significant effect on the development of head shape. Boas argued that if craniofacial features were so malleable in a single generation, then the cephalic index was of little use for defining race and mapping ancestral populations. Scholars such as Earnest Hooton continued to argue that both environment and heredity were involved. Boas did not himself claim it was totally plastic. In 2002, a paper by Sparks and Jantz re-evaluated some of Boas's original data using new statistical techniques and concluded that there was a "relatively high genetic component" of head shape. Ralph Holloway of Columbia University argues that the new research raises questions about whether the variations in skull shape have "adaptive meaning and whether, in fact, normalizing selection might be at work on the trait, where both extremes, hyperdolichocephaly and hyperbrachycephaly, are at a slight selective disadvantage." In 2003, anthropologists Clarence C. Gravlee, H. Russell Bernard, and William R. Leonard reanalyzed Boas's data and concluded that most of Boas's original findings were correct. Moreover, they applied new statistical, computer-assisted methods to Boas's data and discovered more evidence for cranial plasticity. In a later publication, Gravlee, Bernard and Leonard reviewed Sparks's and Jantz's analysis. They argue that Sparks and Jantz misrepresented Boas's claims, and that Sparks's and Jantz's data support Boas. For example, they point out that Sparks and Jantz look at changes in cranial size in relation to how long an individual has been in the United States in order to test the influence of the environment. Boas, however, looked at changes in cranial size in relation to how long the mother had been in the United States. They argue that Boas's method is more useful, because the prenatal environment is a crucial developmental factor. Jantz and Sparks responded to Gravlee et al., reiterating that Boas' findings lacked biological meaning, and that the interpretation of Boas' results common in the literature was biologically inaccurate. In a later study, the same authors concluded that the effects Boas observed were likely the result of population-specific environmental effects such as changes in cultural practices for cradling infants, rather than the effects of a general "American environment" which caused populations in America to converge to a common cranial type, as Boas had suggested.

Vertical cephalic index

The vertical cephalic index, also known as the length-height index, was a less-commonly measured head ratio. In the vertical cephalic index model, humans beings were characterized by having either a chamaecranic (low-skulled), orthocranic (medium high-skulled), or hypsicranic (high-skulled) cephalic index or cranial index.

Medicine

The cephalic index is also used in medicine, especially in the planning and effectiveness analysis of cranial deformity corrections. The index is a useful tool in assessing the morphology of cranial deformities in clinical settings. The index is used while looking at the fetal head shape, and can change in certain situations (ex. breech presentation, ruptured membranes, twin pregnancy). It can be measured for prenatal infants in the womb using obstetric ultrasound, and a value of 78.3% ± 8% (±2 standard deviations) is considered normal.

Modern use in animal breeding

The cephalic index is used in the categorisation of animals, especially breeds of dogs and cats.

Brachycephalic animals

A brachycephalic skull is relatively broad and short (typically with the breadth at least 80% of the length). Dog breeds such as the pug are sometimes classified as "extreme brachycephalic". Because of health issues brachycephaly is regarded in some countries as "qualzucht", which literally translates to "torture breeding" as it often leads to

brachycephalic airway obstructive syndrome Brachycephalic obstructive airway syndrome (BOAS), also known as brachycephalic airway obstructive syndrome (BAOS), brachycephalic airway syndrome (BAS), and brachycephalic syndrome (BS), is a pathological condition affecting brachycephalic, sho ...

List of brachycephalic dogs

* Affenpinscher *

American Bulldog The American bulldog is a large, muscular dog breed, breed of mastiff-type dog. Their ancestors were brought to the British North American colonies where they worked on small farms and ranches. History Dog breeds defined to any standard onl ...

* American Bully * Boston Terrier * Boxer * Brussels Griffon * Bulldog * Bullmastiff * Cane Corso * Cavalier King Charles Spaniel * Apple-headed Chihuahua * Chow Chow * Dogo Argentino * Dogue de Bordeaux * English Mastiff * English Bulldog * Fila Brasileiro * French Bulldog * Japanese Chin * King Charles Spaniel * Lhasa Apso * Lowchen * Neapolitan Mastiff *

Newfoundland Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...

* Olde English Bulldogge * Pekingese * Perro de Presa Canario * Pit bull * Pug * Pyrenean Mastiff * Shar-Pei * Shih Tzu * Tibetan Spaniel * Tosa

List of brachycephalic cats

Nipsu-Nappulan Non-Stop Exotic shorthair

* British Shorthair * Burmese cat * Exotic Shorthair * Himalayan cat * Persian cat * Scottish Fold * White tiger *

Cheetah The cheetah (''Acinonyx jubatus'') is a large Felidae, cat and the Fastest animals, fastest land animal. It has a tawny to creamy white or pale buff fur that is marked with evenly spaced, solid black spots. The head is small and rounded, wit ...

* Leopard * Jaguar * Snow Leopard *

Mountain Lion The cougar (''Puma concolor'') (, ''Help:Pronunciation respelling key, KOO-gər''), also called puma, mountain lion, catamount and panther is a large small cat native to the Americas. It inhabits North America, North, Central America, Cent ...

List of brachycephalic pigs

* Middle White * Neijiang

List of brachycephalic rabbits

* Lionhead rabbit * Lop rabbit * Netherland Dwarf rabbit * Dwarf Papillon rabbit * Dwarf Hotot rabbit * Jersey Wooly rabbit * American Fuzzylop rabbit

Other

Elephant Elephants are the largest living land animals. Three living species are currently recognised: the African bush elephant ('' Loxodonta africana''), the African forest elephant (''L. cyclotis''), and the Asian elephant ('' Elephas maximus ...

* Giant panda * Ross seal * Spectacled bear * Walrus * Wombat * Australian Lowline * brachycephalic

Arabian horse The Arabian or Arab horse ( , DIN 31635, DMG ''al-ḥiṣān al-ʿarabī'') is a horse breed, breed of horse with historic roots on the Arabian Peninsula. With a distinctive head shape and high tail carriage, the Arabian is one of the most easi ...

* Niata cattle *

Tortoise Tortoises ( ) are reptiles of the family Testudinidae of the order Testudines (Latin for "tortoise"). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like o ...

* Raccoon dog * European bison *

Otter Otters are carnivorous mammals in the subfamily Lutrinae. The 13 extant otter species are all semiaquatic, aquatic, or marine. Lutrinae is a branch of the Mustelidae family, which includes weasels, badgers, mink, and wolverines, among ...

Sloth Sloths are a Neotropical realm, Neotropical group of xenarthran mammals constituting the suborder Folivora, including the extant Arboreal locomotion, arboreal tree sloths and extinct terrestrial ground sloths. Noted for their slowness of move ...

Mesaticephalic animals

A mesaticephalic skull is of intermediate length and width. Mesaticephalic skulls are not markedly brachycephalic or dolichocephalic. When dealing with animals, especially dogs, the more appropriate and commonly used term is not "mesocephalic", but rather "mesaticephalic", which is a ratio of head to nasal cavity. The breeds below exemplify this category.

American black bear The American black bear (''Ursus americanus''), or simply black bear, is a species of medium-sized bear which is Endemism, endemic to North America. It is the continent's smallest and most widely distributed bear species. It is an omnivore, with ...

* Brown bear * Brown hyena * Fur seal * Guinea pig * Leopard seal *

Raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the North American, northern or common raccoon (also spelled racoon) to distinguish it from Procyonina, other species of raccoon, is a mammal native to North America. It is the largest ...

* Sea lion * Sloth bear * Spotted hyena * Striped hyena *

Sun bear The sun bear (''Helarctos malayanus'') is a bear species in the Family (biology), family Ursidae found in the tropical forests of Southeast Asia. It is the only species in the genus ''Helarctos'' and the smallest bear species, standing nearly ...

* Tasmanian devil

Dolichocephalic animals

A dolichocephalic skull is relatively long-headed (typically with the breadth less than 80% or 75% of the length). Note: Almost all representatives of the infraphylum Gnathostomata (with rare exceptions) are dolichocephalic.

List of dolichocephalic canids

Note: Almost all canidae are dolichocephalic * Afghan Hound * Airedale Terrier * Azawakh * Basset Hound * Bedlington Terrier * Bloodhound * Borzoi * Bull terrier * Cesky Terrier * Coyote *

Dachshund The dachshund ( or ; German: 'badger dog'), also known as the wiener dog or sausage dog, badger dog, doxen and doxie, is a short-legged, long-bodied, hound-type dog breed. The dog may be smooth-haired, wire-haired, or long-haired, with varie ...

* Doberman Pinscher * Dingo * Fox Terrier * Galgo Español * German Shepherd Dog * Great Dane * Greyhound * Irish Terrier * Irish Wolfhound * Italian Greyhound * Kangaroo hound * Kanni * Kerry Blue Terrier * Khalag Tazi * Long dog * Lurcher * Manchester Terrier * Miniature Bull Terrier * Peruvian Inca Orchid * Pharaoh Hound * Poodle (Standard) * Rampur Greyhound * Rough Collie * Russian Black Terrier * Saluki * Schnauzer * Scottish Deerhound *

Scottish Terrier The Scottish Terrier (; also known as the Aberdeen Terrier), popularly called the Scottie, is a dog breed, breed of dog. Initially one of the highland breeds of terrier that were grouped under the name of ''Skye Terrier'', it is one of five br ...

* Sealyham Terrier * Serbian Hound * Shetland Sheepdog * Silken Windhound * Sloughi * Smooth Collie * Taigan * Welsh Terrier * Whippet *

Wolf The wolf (''Canis lupus''; : wolves), also known as the grey wolf or gray wolf, is a Canis, canine native to Eurasia and North America. More than thirty subspecies of Canis lupus, subspecies of ''Canis lupus'' have been recognized, includin ...

List of dolichocephalic felines

* Balinese * Devon Rex * Donskoy * Jaguar * Javanese * Leopard *

Lion The lion (''Panthera leo'') is a large Felidae, cat of the genus ''Panthera'', native to Sub-Saharan Africa and India. It has a muscular, broad-chested body (biology), body; a short, rounded head; round ears; and a dark, hairy tuft at the ...

Ocelot The ocelot (''Leopardus pardalis'') is a medium-sized spotted Felidae, wild cat that reaches at the shoulders and weighs between on average. It is native to the southwestern United States, Mexico, Central America, Central and South America, ...

* Oriental Bicolor and Tricolor * Oriental Longhair * Oriental Shorthair * ''Panthera'' hybrid * Peterbald * Sabertooth cats * Savannah * Siamese * Snow leopard * Sphynx *

Tiger The tiger (''Panthera tigris'') is a large Felidae, cat and a member of the genus ''Panthera'' native to Asia. It has a powerful, muscular body with a large head and paws, a long tail and orange fur with black, mostly vertical stripes. It is ...

List of dolichocephalic leporids

* English Spot * English Lop * Belgian Hare * All true hares

Other

Baboon Baboons are primates comprising the biology, genus ''Papio'', one of the 23 genera of Old World monkeys, in the family Cercopithecidae. There are six species of baboon: the hamadryas baboon, the Guinea baboon, the olive baboon, the yellow ba ...

* Bontebok * Crocodile * Cow *

Dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutio ...

(including

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s) * Dolphin * Domestic horse *

Donkey The donkey or ass is a domesticated equine. It derives from the African wild ass, ''Equus africanus'', and may be classified either as a subspecies thereof, ''Equus africanus asinus'', or as a separate species, ''Equus asinus''. It was domes ...

* Gharial * Grevy's zebra *

Hartebeest The hartebeest (; ''Alcelaphus buselaphus''), also known as kongoni or kaama, is an Fauna of Africa, African antelope. It is the Monotypic taxon, only member of the genus ''Alcelaphus''. Eight subspecies have been described, including two som ...

* Hyrax * Kangaroo * Mule * Onager *

Plains zebra The plains zebra (''Equus quagga'', formerly ''Equus burchellii'') is the most common and geographically widespread species of zebra. Its range is fragmented, but spans much of southern and eastern Africa south of the Sahara. Six or seven subspec ...

* Polar bear *

Thylacine The thylacine (; binomial name ''Thylacinus cynocephalus''), also commonly known as the Tasmanian tiger or Tasmanian wolf, was a carnivorous marsupial that was native to the Mainland Australia, Australian mainland and the islands of Tasmani ...

* Warthog *

Whale Whales are a widely distributed and diverse group of fully Aquatic animal, aquatic placental mammal, placental marine mammals. As an informal and Colloquialism, colloquial grouping, they correspond to large members of the infraorder Cetacea ...

* Wild boar * Wildebeest

References

External links

Cephalic index

Brachycephalic Experienced Veterinarians Database
{{DEFAULTSORT:Cephalic Index Biological anthropology

Historic use in anthropology

Early anthropology

Indices

Controversy

Vertical cephalic index

Medicine

Modern use in animal breeding

Brachycephalic animals

List of brachycephalic dogs

List of brachycephalic cats

List of brachycephalic pigs

List of brachycephalic rabbits

Other

Mesaticephalic animals

List of mesaticephalic canines

List of mesaticephalic cats

List of mesaticephalic rabbits

Other

Dolichocephalic animals

List of dolichocephalic canids

List of dolichocephalic felines

List of dolichocephalic leporids

Other

See also

References

External links