Personality psychology is a branch of psychology that studies personality and individual differences. Its areas of focus include: Constructing a coherent picture of a person and his or her major psychological processes Investigating individual differences, that is, how people can differ from one another Investigating human nature, that is, how all people's behaviour is similar"Personality" can be defined as a dynamic and organized set of characteristics possessed by a person that uniquely influences his or her cognitions, motivations, and behaviors in various situations. The word "personality" originates from the Latin persona, 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.