/anthropology/glossary/somatotype
A somatotype is a description of body build by three components: endomorphy, the relative roundness and fatness of the body; mesomorphy, its relative muscular and skeletal robustness; and ectomorphy, its relative linearity. The scheme is Sheldon's, of 1940, and it differs in kind from the other measures in this glossary. It is not an index, for there is no ratio; each component is rated on a scale, and a somatotype is the three ratings taken together, so that 1-7-1 is an extreme mesomorph and 4-4-4 a build in which no component leads. The corpus names a population by its leading component alone, and since the three words are among the commonest in its descriptions, it matters to know what has been dropped in reducing three ratings to one word, and from what history the words come.
Status: Preliminary. The methods are given from the primary works; the corpus's source states that it uses Sheldon's classes "in a slightly modified manner" without saying how.
ecto- ἐκτός outside · meso- μέσος middle · endo- ἔνδον within · -morph μορφή form · pyknic πυκνός thick, compact · leptosome λεπτός, σῶμα slender body
The three names are borrowed from the germ layers of the embryo. Sheldon held that the gut, which forms from the endoderm, predominates in the round build; muscle and bone, from the mesoderm, in the robust; and skin and nervous system, from the ectoderm, in the linear. The embryology was a figure of speech rather than a finding and was not pursued, but the names outlived it. Kretschmer's earlier scheme has the plainer vocabulary: leptosome or asthenic for the slender build, athletic for the muscular, and pyknic for the compact and fat.
Sheldon rated from photographs. The subject was photographed nude from the front, side and back at a fixed distance; seventeen diameters were measured on the prints and divided by stature; and each component was rated from 1 to 7 by comparison with standard series. The ratings were then adjusted by inspection, so that the final instrument was Sheldon's own eye, a fact of consequence for the history that follows.
Heath and Carter replaced the photographs with the anthropometer and the caliper in 1967. Endomorphy is rated from the sum of three skinfolds, at the triceps, below the shoulder blade and above the hip, corrected for stature; mesomorphy from the breadths of the elbow and knee and the girths of the flexed arm and the calf, the girths corrected for skinfold, all set against stature; and ectomorphy from the ratio of stature to the cube root of weight. The scales are open at the top, and because the components can be computed by anyone from the measurements, the Heath-Carter somatotype is the one that remains in use.
Three schemes stand behind the corpus's words. They are not cuts of one scale, as the classes of an index are, but three ways of dividing the same ground, and the table sets them beside one another so that the correspondence can be seen.
| Build | Kretschmer (1921) | Sheldon (1940) | Heath and Carter (1967) |
|---|---|---|---|
| slender, linear | leptosome, asthenic | ectomorph | ectomorph, and the mixed categories (mesomorphic ectomorph, ectomorphic mesomorph) |
| muscular, robust | athletic | mesomorph | mesomorph and its mixed categories |
| compact, fat | pyknic | endomorph | endomorph and its mixed categories |
| no component leading | (dysplastic, for builds that fit none) | a midrange rating such as 4-4-4 | central |
Sheldon rated each component from 1 to 7, Heath and Carter on open scales usually falling between 1 and 9; Heath and Carter name thirteen categories by which components lead and by how much. Kretschmer's are types, not ratings.
The corpus's source uses Sheldon's three words and uses them as types, in Kretschmer's manner: a population is ectomorph, mesomorph or endomorph, and where it straddles two the source writes "ecto- to mesomorph". No ratings are given. Two further conditions are stated by the source and should be carried with the words: its classes describe indigenous groups under their own diet, and its illustrations are extreme European examples that most groups do not approach.
The division of bodies into the slender and the stout is as old as medicine; the Hippocratic writings distinguish the habitus phthisicus, prone to consumption, from the habitus apoplecticus. Ernst Kretschmer gave the division its modern form in 1921, in Körperbau und Charakter, where the three builds were set against the psychoses, the leptosome against schizophrenia and the pyknic against manic-depressive illness. The book was a work of psychiatry, and the builds were its instrument rather than its subject.
William Sheldon took the instrument and remade it. The Varieties of Human Physique of 1940 introduced the three components, the seven-point ratings and the photographic method; The Varieties of Temperament of 1942 set a temperament against each component and reported correlations near 0.8 between build and character; and the Atlas of Men of 1954 printed the photographic standards. The photographs were taken on a large scale at American colleges over three decades, and the practice ended in the 1960s amid objections that have attached to the method since.
The claims about temperament did not survive examination. Sheldon had rated both physique and temperament himself, and independent studies found the correlations small. The ratings of physique survived on their own merits. Barbara Heath, who had worked with Sheldon, and Lindsay Carter rebuilt the method on measurements in 1967, and their somatotype is the standard in the study of athletes and of growth. The anthropological typologies of the mid-century, meanwhile, had adopted Sheldon's words loosely for the usual build of a population, and that is the use the corpus inherits.
The components measure real things, the fat, the muscle and bone, and the linearity of a body at the time of measurement. Rated by the Heath-Carter method they are reliable between observers, and they distinguish athletes by their events and populations by their builds.
Sheldon held that a somatotype was fixed, a genotype that neither diet nor training could move. It is not. Endomorphy follows diet, mesomorphy follows work, and both change with age; the corpus's source says as much in its own terms, observing that Western nutrition has raised the stoutness of Native American and Polynesian populations well above the values its classes describe. A somatotype is therefore a description of a population under a diet at a date, and the source's classes carry, by its own statement, the condition of an indigenous diet.
The heritable part is real but unevenly distributed among the components. Linearity, which is largely stature and bone, is inherited much as stature is; fatness is the component most under the control of circumstance. It follows that a population's ectomorphy says more about its ancestry than its endomorphy does, and that the three words are not equal witnesses.
The source's own observation is the most useful: all builds occur in all populations, in differing proportions, so that the class is a mode and not a bound. There are slender and muscular Mongols, the source says, though endomorphy is the commoner build in Mongolia; and short, stocky Nilotes are nearly unknown. A description by leading component states where the centre of a population lies and nothing about its edges.
Build follows climate in part. The source cites Allen's rule for the slender bodies of hot dry country and Bergmann's for the large compact bodies of the cold, with Rohrer's index highest among the Inuit and lowest among the Nilotes. The rules describe the extremes well; in the middle of the world, where diet, work and descent are confounded, they describe little.
The doctrine of temperament from which the scheme came forms no part of the corpus's use and no part of the evidence. It is the reason the word carries a reputation, and the reason the method had to be rebuilt; and a reader who meets the words in the corpus should know that only the rebuilt part is in play.
Of the 209 local varieties, 205 are given a somatotype. Nineteen are written as a range, "meso- to endomorph", and are counted under both components.
| Component | Types | Examples |
|---|---|---|
| ectomorph | 123 | Aetid, Alföld, Amur-Sakhalin, Anatolid |
| mesomorph | 89 | Aisto Nordid, Andronovo-Turanid, Anglo-Saxon |
| endomorph | 106 | African Alpinoid, Arabian Veddoid, Berberid |
Ectomorphy leads, as it should if the source's condition is taken seriously: under a diet of hunting, herding or early agriculture most populations are slender, and the classes describe that condition and not the present one.
Stature, which ectomorphy largely restates. Relative trunk length, for the proportion that build does not capture. Build, for the plainer words gracile and robust the corpus uses beside these. The morpheme grid.
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