Type/Constitutional/Biological Theories of personality:
Greek physician and philosophers Hippocrates and Galen claimed that a person's temperament depends on relative quantities of four humors, or fluids, in the body—blood (sanguine) and cheerfulness, phlegm (phlegmatic) and calmness, black bile (melancholic) and depression, yellow bile (choleric) and irritability.
Gall and Spurzheim related bumps and depressions on the skull to personality traits in their theory of phrenology.
William Sheldon related physique to temperament. According to his somatotype theory the soft, spherical endomorph is likely to be sociable and affectionate; the hard, muscular mesomorph is likely to be aggressive and courageous; and the linear and fragile ectomorph is likely to be restrained and happy to be alone.
German psychiatrist Ernst Kretschmer wrote a frail, rather weak (asthenic) body build as well as a muscular (athletic) physique were frequently characteristic of schizophrenic patients, while a short, rotund (pyknic) build was often found among manic-depressive patients.
Friedman and Rosenman gave Type A and Type B theory, that relates type to the disease.
Trait theorists try to describe basic behaviors that define personality and they assume that we each have relatively stable personality characteristics or dispositional attributes, called traits.
Gordon Allport defined traits into three categories: cardinal traits, central traits and secondary traits. This interpretation emphasizes that all traits are interdependent sets of attributes which come together to produce...