- Of or pertaining to an ectomorph.
Constitutional psychology is a theory, developed in the 1940s by American psychologist William Sheldon, associating body types with human temperament types. Sheldon proposed that the human physique be classed according to the relative contribution of three fundamental elements, somatotypes, named after the three germ layers of embryonic development: the endoderm, (develops into the digestive tract), the mesoderm, (becomes muscle, heart and blood vessels), and the ectoderm (forms the skin and nervous system).
In his 1954 book, Atlas of Men, Sheldon categorised 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.
The Three Types
Sheldon’s “somatotypes” and their supposed associated psychological traits can be summarised as follows:
- Ectomorphic: characterized by long and thin muscles/limbs and low fat storage; usually referred to as slim.
- Mesomorphic: characterized by large bones, solid torso, low fat levels, wide shoulders with a narrow waist.
- Endomorphic: characterized by increased fat storage, a wide waist and a large bone structure.
The idea that these general body-types may correlate with general psychological types did not originate with Sheldon. In general outline it resembles ideas found, for instance, in the Bhagavad Gita and Plato's "Republic" and propounded in the twentieth century by George Gurdjieff. Sheldon's ideas may also owe something to Aristotle's concept of the soul.
Roughly the three corresponding personality types proposed by Sheldon are somewhat akin to Jung's categorisation of thinking, feeling and sensing types. As such they correspond quite closely to popular stereotypes of the skinny nerd, the jolly fat man, the slow-witted tough.
There is evidence that different physiques carry 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. Stereotypes of mesomorphs are generally much more favorable than those of endomorphs. Stereotypes of ectomorphs are somewhat mixed.
The three body type descriptions could be modulated by body composition, which can be altered by specific diets and training techniques. In a famine a person who was once considered an endomorph may begin to instead resemble an ectomorph, while 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: muscle and adipose mass may change but the bone structure is a fixed characteristic. In the same way, cultural conditions might mask a tendency to one or another temperament.
Sheldon failed to produce a personality test that supported his notions statistically. His research did show that a predisposition towards criminality might be influenced by a somatotype high in endomorphy and intermediate in mesomorphy. In contrast, a predisposition towards suicidality might be influenced by a somatotype high in ectomorphy, and ectomorphs were found to be more common in mental institutions. These tendencies might be taken to support a theory of the aggressive and the nervous temperament, but no coherent demonstration of Sheldon's ready-made thesis has been forthcoming.
Sheldon's theories had popularity through the 1950s, influencing Abraham Maslow, Aldous Huxley and Robert S de Ropp.The majority of scientists today generally consider such theories outdated. Some found the idea of somatotypes reminiscent of eugenics and racial hygiene, they went against the fashionable emphasis on nurture, presenting a ready-made paradigm that had strong resonances with mystical thought.
Sheldon's 4,000 photographs of naked Yale undergraduates and other similar photographs were destroyed.
The words endomorphic, mesomorphic and ectomorphic are still sometimes used to describe body types, as for example in association with weight training aimed at gaining muscle, but interest in this kind of correlation between physiology and psyche remains largely the province of the occult philosopher. The psycho-somatic linkage is fairly simplistic and is seen as undemonstrated in physiological science, but the account of somatotypes is still probably a valid, if limited, way to sort basic body types. Advanced triploblastic animals, such as mammals, or modern humans in particular, do have these three basic tissue layers.
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. 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. It is not a large leap to consider a role for different patterns of somatosensory input in persons with different body types.
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 prevalence of kindred ideas in folklore and spiritual philosophy, though, suggests that ideas similar to Sheldon's will continue to be held until they are conclusively proven or disproven.
- 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.
- The Life and Times of an Endomorphic Mexican: Alex Quinn. Canada, 1991.
- 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
- About William Sheldon at Age of the Sage
- Somatotypes at kheper.net
- Webmd.com - Morph your Body Type
- Fitness-Web.com - Choosing the right exercise for your body type
- ChangingMinds.org - Wiliam Sheldon's body types
- About.com - Ectomorphs
- Britannica.com - Ectomorph
- VistaMagOnline.com - The enigma of the ectomorph
- About.com - Mesomorph, article: "Body shapes what do they mean?"
- Britannica.com - Mesomorph
ectomorphic in German: Körperbautyp
ectomorphic in French: Somatotype
ectomorphic in Icelandic: Líkamsgerð
ectomorphic in Portuguese: Somatótipo
ectomorphic in Slovak: Somatotyp
ectomorphic in Finnish: Somatotyypit
ectomorphic in Swedish: Somatyper