Somatotypes

The somatotypes is the core of a theory based on the assumption that different body types are associated with human temperament types, formed during the 1940s by the American psychologist William Sheldon. While this linkage may be simplistic and is seen as outdated in physiological science, it is still probably a valid way to sort out the basic body types, and common sense demonstrates at least a "kernel" of truth to the influence of the three contributing layers of an advanced "triploplastic" animal, such as a mammal, or a modern human in particular. If you were to disect a cadaver, and weigh the tissue broken down into the 3 layers of origin, you do obtain results that support Sheldon's thesis, but only to a degree. Sheldon was, after all, a "behavior" centered researcher, not so much an anatomist, or physiologist. Some of this is useful general and human biology, if weak "behavioral science".

Using anthropometric methods Sheldon studied the photographed bodies of some 4,000 men from front view, side view, and back view. 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" can be summarised as follows:

Please take care to see this in its historical context. Even if his behavioral conclusions are almost laughable, the physical traits are still a useful way to defining body types. Filtered for "stereotypical" conclusions, there is base-line for future research, where a "pinch" of his thesis can be reconciled with what we have learned over the past 65 years.


 * The endomorphic body type is centered around the digestive system and is easily overweight. The endomorphic person also has a visceral temperament, which means that they are tolerant, love comfort and luxury, and are extroverted - in short he or she loves food and people.  Jolly Fat Person  stereotype.


 * The mesomorphic body type is centered around muscle and the circulatory system and has well developed muscles. The mesomorphic person has a somatotonic temperament, and is courageous, energetic, active, dynamic, assertive, aggressive, competitive, and often a risk taker.  The Jock or GI-Joe  stereotype.


 * The ectomorphic body type is centered around the brain and nerves. These people are slim and possibly underweight. The ectomorphic person has a cerebrotonic temperament, and is artistic, sensitive, apprehensive and highly self-aware. A more negative way to put it is that he or she is introverted and socially restrained.  Range: Gay Dancer-Hetero-Geek  stereotype.

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 truly endomorph is 7-1-1, the pure mesomorph 1-7-1 and the 100 % ectomorph scores 1-1-7. From this, assessment of the individual's mental caracteristics could be made. Sheldon assumed that a predisposal for criminality might be influenced by the mix of an individual's body type formula. Perhaps, he fully believed that, but we are free to use the convenient body type models to construct our own, hopefully less stereotypical, view of the influence of body "wiring" and hormonal factors, on mind and personality traits.

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 (see Body type (exercise)). In some types of New Age there is an interest in this kind of correlation between physiology and psyche, but the science of today generally consider these "sweepingly broad" theories from the 30s and 40s, outdated at best.

Health danger from trying to change one's body-type perception
Researchers have noted that many Americans growing up in and after the period of Sheldon's work consciously tried to "morph" into a different somatotypic group. Nobody wanted to be the proverbial 98-pound weakling. Many slender men consciously "carbed up" to gain an unhealthful forty extra pounds so that they could look more like the stereotypical mesomorphic "Jock". These same men may now be more obese than they appear, or may have even died from the transformation. Seventy pounds over ideal weight for your true body type can be deadly.

The Chipmunk characters Alvin (mesomorph), Simon (ectomorph), and Theodore (endomorph) adhere strongly to Sheldon's types in both mind and body.