Personality psychology is a branch of psychology which studies personality and individual different processes - that which makes us into a person. One emphasis is on trying to create a coherent picture of a person and all his or her major psychological processes. Another emphasis views it as the study of individual differences. These two views work together in practice. Personality psychologists are interested in broad view of the individual. This often leads to an interest in the most salient individual differences among people.
The word originates from the Latinpersona, which means "mask."
Significantly, in the theatre of the ancient Latin-speaking world, the mask was not used as a plot device to disguise the identity of a character, but rather was a convention employed to represent, or typify that character.