To an extent, psychology is the study of individual differences among people. Individuals are not identical to one another; they differ in their thoughts, feelings, motivations, personalities, likes, dislikes, preferences, habits, and behaviors. Psychology seeks to identify these differences and explain them. For example, psychologists seek to understand why people react differently to particular situations and stimuli.
Psychology of difference is an extensive area of study, where psychologists try to understand the differences between people. A good example of this comes from the field of personality psychology; two individuals can show similar traits, yet act very differently. Another example is intelligence testing; someone may perform poorly compared to others, however, in a task designed to measure intelligence, the same person may do quite well. In both cases, psychologists have devised questions to help identify what makes each person unique, and how those characteristics affect them. This is sometimes referred to as clinical psychology because it focuses on problems and disorders. However, there are also fields of research that examine the similarities among people, including developmental psychology and evolutionary psychology.
