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The three somatotypesendomorphic, mesomorphic, and ectomorphic—are basic classifications of animal body types according to the prominence of different basic tissues types, roughly: digestive, muscular, and nervous tissues. They form the core of a theory, developed in the 1940s by American psychologist William Sheldon, associating body types with human temperament types. This linkage is fairly simplistic and is seen as outdated in physiological science, but the account of somatotypes is still probably a valid, if limited way to sort basic body types.

He concluded that the physique of men can be divided into the contribution of three fundamental elements: the somatotypes. He named his somatotypes after the three germ layers of embryonic development: the endoderm, that develops into the digestive tract, the mesoderm, that is to become muscle, heart and blood vessels, and the ectoderm that is to form the nervous system. Sheldon’s “somatotypes” and their (presumed and supposed) associated psychological traits can be summarised as follows:

  • Ectomorphic body type (sometimes referred to as the "banana") is characterized by long arms and legs and a short upper body, high forehead, slightly narrow shoulders, and supposedly have a higher proportion of nervous tissue. They also have long and thin muscles. Ectomorphs usually have a very low fat storage; therefore they are usually referred to as slim. Famous ectomorphs include Angelina Jolie, Johnny Depp, Kate Moss, footballer Peter Crouch and swimmer Mark Foster.
  • Mesomorphic body type is (sometimes referred to as "hourglass" for a female and "rectangle" for a male) characterized by a high rate of muscle growth and a higher proportion of muscular tissue. They have large bones, solid torso combined with low fat levels. It is also noted that they have wide shoulders with a narrow waist. Famous mesomorphs include Mariah Carey, Oprah Winfrey, Bruce Willis and Alicia Keys.
  • Endomorphic body type (sometimes referred as "apple" for those who put most muscle and fat on the top half of the torso, and "pear" for those who put most muscle and fat on the bottom half of the torso) is characterized by an increased amount of fat storage, due to having a larger number of fat cells than the average person, as well as higher proportion of digestive tissue. They have a wide waist and a large bone structure. Famous endomorphs include Sarah Michelle Gellar (pear), Catherine Zeta-Jones (apple), Jack Black (apple) or Meat Loaf (apple)

In his book, Atlas of Men, Sheldon categorised all possible body types according to a scale ranging from 1 to 7 for each of the 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. Sheldon's research showed that a predisposition towards criminality might be influenced by a somatotype high in endomorphy and intermediate in mesomorphy, and in contrast, a predisposition towards suicidality might be influenced by a somatotype high in ectomorphy; on the other hand, ectomorphs were found to be more common in mental institutions.

Additional recommended knowledge


Modern assessments

Some of this is useful in general and human biology, if weak behavioral science. Advanced triploblastic animals, such as mammals, or modern humans in particular, do have these three basic tissue layers. Sheldon himself was more a behavioral psychologist than either an anatomist or a physiologist. His behavioral conclusions were based largely on interviews which he or his students carried out over a long span of time, and the actual psychometric data was often more suggestive than conclusive. The physical traits are still a useful way of defining body types, and filtered of these conclusions, may provide a base-line for future research.

Changing somatotypes

The three body type descriptions could be explained as differences in body composition, which can be altered by specific diets and training techniques.

After a period of significant weight loss, a person who was once considered an endomorph may begin to instead resemble an ectomorph (see Rhea Bhadresha, during the period 1999-2006). Likewise, an athletic mesomorph may begin to look more like an endomorph as he ages and loses muscle mass.

However, some aspects of the Somatotype cannot be changed, for example, a characteristic of an endomorphic body type is wide shoulders as well as a wide waist. Ectomorphs may have narrower shoulders and slimmer waists. Although, muscle and adipose mass can be changed, the bone structures associated with endomorphs, ectomorphs and mesomorphs means completely changing between two somatotypes is not always possible.

Stereotypes of somatotypes

There is evidence that people with different physiques are targeted by cultural stereotypes. For example, one study found that 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 but fearful.[1] Stereotypes of mesomorphs are generally much more favorable than those of endomorphs. Stereotypes of ectomorphs are somewhat mixed.

Reaction against somatotype theory and research

The majority of scientists today generally consider these theories from the 1930s and 1940s outdated. Sheldon's theories had popularity through the 1950s. Some saw in the somatotypes a link to eugenics and racial hygiene. Sheldon's 4,000 photographs of nude Yale undergraduates and other similar photographs were destroyed.[2][3] The words endomorphic, mesomorphic and ectomorphic are still sometimes used to describe body types, maybe especially in association with weight training aimed at gaining muscle. In some types of New Age there is an interest in this kind of correlation between physiology and psyche.

Sheldon's ideas were a variation on an old idea, beginning with Aristotle's concept of the "vegetative soul".[citation needed] Different versions of the notion are attracting new interest. Harvard psychologist Jerome Kagan has convincingly shown the existence of inborn temperament across diverse cultures, linking cardinal traits to neurochemical activation patterns involving the autonomic nervous system.[citation needed] Antonio Damasio's theory of frontal lobe function, the somatic markers hypothesis, posits goal-directed behavior as primarily directed by heavy somatosensory input from the internal milieu.[citation needed] It is not a large leap to consider a role for different patterns of somatosensory input in persons with different body types.[citation needed]


  1. ^ Ryckman, R. M., Robbins, M. A., Kaczor, L. M., & Gold, J. A. (1989). Male and female raters' stereotyping of male and female physiques. Personality and Social Psychology Bulletin, 15, 244-251.
  2. ^ Rosenbaum, Ron The Great Ivy League Nude Posture Photo Scandal. New York Times January 15, 1995
  3. ^ Nude Photos of Yale Graduates Are Shredded New York Times January 29, 1995


  • William Sheldon. The Varieties of Human Physique: An Introduction to Constitutional Psychology. New York: Harper, 1940.
  • The Varieties of Temperament: A Psychology of Constitutional Differences. New York: Harper, 1942.
  • Varieties of Delinquent Youth: An Introduction to Constitutional Psychiatry. New York: Harper, 1949.
  • Atlas of Men: A Guide for Somatotyping the Adult Male at All Ages. New York: Harper, 1954.
  • Emil M. Hartl, Edward P. Monnelly, and Roland D. Elderkin. Physique and Delinquent Behavior: A Thirty-year Follow-up of William H. Sheldon’s Varieties of Delinquent Youth. New York: Academic Press, 1982.
  • Psychology and Life, 7 ed. by Richard Gerrig and Phillip G. Zimbardo

See also

  • - Ectomorphs
  • - Ectomorph
  • - The enigma of the ectomorph
  • - Mesomorph, article: "Body shapes what do they mean?"
  • - Mesomorph
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Somatotype". A list of authors is available in Wikipedia.
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