Somatotype and Constitutional Psychology - The Three Types

The Three Types

Sheldon's "somatotypes" and their supposed associated physical traits can be summarized as follows:

• Ectomorphic: characterized by long and thin muscles/limbs and low fat storage; usually referred to as slim. Ectomorphs are not predisposed to store fat or build muscle.
• Mesomorphic: characterized by medium bones, solid torso, low fat levels, wide shoulders with a narrow waist; usually referred to as muscular. Mesomorphs are predisposed to build muscle but not store fat.
• Endomorphic: characterized by increased fat storage, a wide waist and a large bone structure, usually referred to as fat. Endomorphs are predisposed to storing fat.

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 or she 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.