From Wikipedia:

Personality psychology is a branch of psychology that studies personality and its variation among individuals. It is a scientific study which aims to show how people are individually different due to psychological forces.[1] Its areas of focus include:

  • construction of a coherent picture of the individual and their major psychological processes
  • investigation of individual psychological differences
  • investigation of human nature and psychological similarities between individuals

“Personality” is a dynamic[clarification needed] and organized set of characteristics possessed by a person that uniquely[clarification needed] influences their environment, cognitionsemotionsmotivations, and behaviors in various situations. The word personality originates from the Latin persona, which means “mask“.

Personality also refers to the pattern of thoughtsfeelingssocial adjustments, and behaviors consistently exhibited over time that strongly influences one’s expectations, self-perceptionsvalues, and attitudes. Personality also predicts human reactions to other people, problems, and stress.[2][3] Gordon Allport (1937) described two major ways to study personality: the nomothetic and the idiographicNomothetic psychology seeks general laws that can be applied to many different people, such as the principle of self-actualization or the trait of extraversionIdiographic psychology is an attempt to understand the unique aspects of a particular individual.

The study of personality has a broad and varied history in psychology with an abundance of theoretical traditions. The major theories include dispositional (trait) perspective, psychodynamic, humanistic, biological, behaviorist, evolutionary, and social learning perspective. However, many researchers and psychologists do not explicitly identify themselves with a certain perspective and instead take an eclectic approach. Research in this area is empirically driven, such as dimensional models, based on multivariate statistics, such as factor analysis, or emphasizes theory development, such as that of the psychodynamic theory. There is also a substantial emphasis on the applied field of personality testing. In psychological education and training, the study of the nature of personality and its psychological development is usually reviewed as a prerequisite to courses in abnormal psychology or clinical psychology.