From embryology we know that our bodies are organized around three basic cell types: endoderm, mesoderm and ectoderm. As we grow these cell types attempt to maintain  set ratios to each other. However, this ratio is an approximation and in almost everyone, there is a relative dominance or deficit of one or two of these cell types. This “imbalance” can be observed in the appearance of the physiology of an individual1.

The emergence of these cell types follows our evolutionary trajectory. The specialized adaptations animals acquired required specialized cell functions. For example, movement required muscle and skeletal cells (Mesoderm). Somatotyping can thereby be linked to the Dimensional Mastery Model, offering visual cues as to which dimensional realm is most dominant and hinting at which therapeutic strategies cataloged in the model would have greater efficacy. It is likely that somatotyping is done either consciously or unconsciously by all effective therapists.



Endomorph: Point
The foundational cell type in our bodies is Endoderm which forms our viscera and organs. This can be thought of as the cell type which shares a common ancestor with all organisms. It is this tissue type that handles the basic processes of life.

Endomorphs are generally more social, more able to simply be present in the moment. Their emotional reactivity trends to grief.



 Mesomorph: Line
Movement required the emergence of a cell type to handle this specialized task. Mesoderm is the tissue type of our muscles and skeleton, which we share in some variation with all organisms which move.

Mesomorphs are more action oriented, often taking the role of leader in getting things done. Their experience of time is more linear, comfortable stepping through a plan to achieve a goal. Their emotional reactivity trends to anger.




 Ectomorph: Plane
While animals were figuring out the how of movement, they also needed to figure out the where and why. This required the development of complex sensory systems, and the ability to think through the relevance of what they were sensing. Ectoderm is the tissue type of our nervous system.

Their emotional reactivity trends to fear.

 Mixed Somatotypes: Space
The diagrams above illustrate quite pure forms of tissue type dominance, which are rare. We almost always fall into a blend somewhere in the middle of these three types, making assessment somewhat more challenging. These charts illustrate for men and women where we tend to cluster.





The Enneagram and Somatotypes

There is a linkage between Somatotypes and a model used for assessing how individuals process their experience called the Enneagram. Through Somatotypes, we can use the Enneagram as a lens for the Dimensional Mastery Model. This linkage is presented here without explanation:

ENDOMORPHS tend to express on points 2, 3 and 4

ECTOMORPHS tend to express on points 5, 6, and 7

MESOMORPHS tend to express on points 8, 9 and 1

1: “Atlas of Men, A Guide and Handbook on Somatotyping” William H. Sheldon 1954