Type theorists have explained personality on the basis of physique and temperament. Temperament refers to the emotional aspects of the personality like changes in mood, tensions, excitement, etc.
In the 1940s, William Herbert Sheldon associated body types with human temperament types. He claimed that a body type could be linked with the personality of that person. He says that a fat person with a large bone structure tends to have an outgoing and more relaxed personality while a more muscular body-typed person is more active and aggressive. A slim or scrawny person with thin muscles is usually characterized as quiet or fragile. He split up these body/personality types into three categories called somatotypes such as ectomorphic, mesomorphic, and endomorphic.
German psychologist Kretschmer has attempted to correlate physique and character. From his studies on mental patients, he found that certain body types are associated with particular types of mental disorders. He has classified personalities into four types as Pyknic, Asthenic, Athletic and Dysplastic type.
