Somatotype is a taxonomy developed in the 1940s by American psychologistWilliam Herbert Sheldon to categorize the human physique according to the relative contribution of three fundamental elements which he termed 'somatotypes', classified by him as 'ectomorphic', 'mesomorphic' and 'endomorphic'. He named these after the three germ layers of embryonic development: the endoderm,, the mesoderm, and the ectoderm. Later variations of the methodology, developed by his original research assistant Barbara Heath, and later Lindsay Carter and Rob Rempel are still in occasional academic use. Constitutional psychology is a theory developed by Sheldon in the 1940s, which attempted to associate his somatotype classifications with human temperament types. The foundation of these ideas originated with Francis Galton and eugenics. Sheldon and Earnest Hooton were seen as leaders of a school of thought, popular in anthropology at the time, which held that the size and shape of a person's body indicated intelligence, moral worth and future achievement. In his 1954 book, Atlas of Men, Sheldon categorized all possible body types according to a scale ranging from 1 to 7 for each of the three 'somatotypes', where the pure 'endomorph' is 7–1–1, the pure 'mesomorph' 1–7–1 and the pure 'ectomorph' scores 1–1–7. From type number, an individual's mental characteristics could supposedly be predicted. In a late version of a pseudoscientific thread within criminology in which criminality is claimed to be an innate characteristic that can be recognized through particular physiognomic markers, Sheldon contended that criminals tended to be 'mesomorphic'. The system of somatotyping is still in use in the field of physical education.
The three types
Sheldon's "somatotypes" and their associated physical and psychological traits were characterized as follows:
Ectomorphic: characterized as skinny, weak, and usually tall; described as intelligent, gentle and calm, but self-conscious, introverted and anxious.
Mesomorphic: characterized as hard, muscular, thick-skinned, and as having good posture; described as competitive, extroverted, and tough.
Endomorphic: characterized as fat, usually short, and having difficulty losing weight; described as outgoing, friendly, happy and laid-back, but also lazy and selfish.
Stereotyping
There may be some evidence that different physiques carry cultural stereotypes. According to one study endomorphs are likely to be perceived as slow, sloppy, and lazy. Mesomorphs, in contrast, are typically stereotyped as popular and hardworking, whereas ectomorphs are often viewed as intelligent, yet fearful.
Heath-Carter Formula
Sheldon's physical taxonomy is still in use, particularly the Heath-Carter variant of the methodology. This formulaic approach utilises an individual's weight, height, upper arm circumference, maximal calf circumference, femur breadth, humerus breadth, triceps skinfold, subscapular skinfold, supraspinal skinfold, and medial calf skinfold, and remains popular in anthropomorphic research, as to quote Rob Rempel "With modifications by Parnell in the late 1950s, and by Heath and Carter in the mid 1960s somatotype has continued to be the best single qualifier of total body shape". This variant utilizes the following series of equations to assess a subject's traits against each of the three somatotypes, each assessed on a seven-point scale, with 0 indicating no correlation and a 7 a very strong: where:
Ectomorphy : Calculate the subjects Ponderal Index:
* If,
* If,
* If,
This numerical approach has gone on to be incorporated in the current sports science and physical education curriculums of numerous institutions, ranging from the UK's secondary level GCSE curriculums, the Indian UPSC Civil Service exams, to MSc programs worldwide, and has been utilized in numerous academic papers, including:
Sheldon's ideas that body type was an indicator of temperament, moral character or potential—while popular in an atmosphere accepting of the theories of eugenics—were later disputed. A key criticism of Sheldon's constitutional theory is that it was not a theory at all but a general assumption of continuity between structure and behavior and a set of descriptive concepts to measure physique and behavior in a scaled manner. His use of thousands of photographs of naked Ivy League undergraduates, obtained without explicit consent from a pre-existing program evaluating student posture has been strongly criticized. While popular in the 1950s, Sheldon's claims have since been dismissed as "quackery". Barbara Honeyman Heath, who was Sheldon's main assistant in compiling Atlas of Men, accused him of falsifying the data he used in writing the book.
