The morphic body types refer to common body shapes found in the human population. The terms are ectomorph, endomorph, and mesomorph. These terms fall under a general term known as somatotype. The term was developed by psychologist William Sheldon, who assigned personality traits to a person’s morphic proportions. The theory between body type and personality traits has since been proven false. The terms still are used in fitness vernacular. Ectomorph refers to a person who is slender. Endomorph describes a person with mostly body fat composition. The mesomorphic body type describes a muscular body.