Personality

The unique pattern of psychological and behavioral characteristics by which each person can be distinguished from other people.

Personality is fundamental to the study of psychology. The major systems evolved by psychiatrists and psychologists since Sigmund Freud to explain human mental and behavioral processes can be considered theories of personality. These theories generally provide ways of describing personal characteristics and behavior, establish an overall framework for organizing a wide range of information, and address such issues as individual differences, personality development from birth through adulthood, and the causes, nature, and treatment of psychological disorders.

Type theory of personality

Perhaps the earliest known theory of personality is that of the Greek physician Hippocrates (c. 400 B.C.), who characterized human behavior in terms of four temperaments, each associated with a different bodily fluid, or "humor." The sanguine, or optimistic, type was associated with blood; the phlegmatic type (slow and lethargic) with phlegm; the melancholic type (sad, depressed) with black bile; and the choleric (angry) type with yellow bile. Individual personality was determined by the amount of each of the four humors. Hippocrates' system remained influential in Western Europe throughout the medieval and Renaissance periods. Abundant references to the four humors can be found in the plays of Shakespeare, and the terms with which Hippocrates labeled the four personality types are still in common use today. The theory of temperaments is among a variety of systems that deal with human personality by dividing it into types. A widely popularized (but scientifically dubious) modern typology of personality was developed in the 1940s by William Sheldon, an American psychologist. Sheldon classified personality into three categories based on body types: the endomorph (heavy and easy-going), mesomorph (muscular and aggressive), and ectomorph (thin and intellectual or artistic).

Trait theory of personality

A major weakness of Sheldon's morphological classification system and other type theories in general is the element of oversimplification inherent in placing individuals into a single category, which ignores the fact that every personality represents a unique combination of qualities. Systems that address personality as a combination of qualities or dimensions are called trait theories. Well-known trait theorist Gordon Allport (1897-1967) extensively investigated the ways in which traits combine to form normal personalities, cataloguing over 18,000 separate traits over a period of 30 years. He proposed that each person has about seven central traits that dominate his or her behavior. Allport's attempt to make trait analysis more manageable and useful by simplifying it was expanded by subsequent researchers, who found ways to group traits into clusters through a process known as factor analysis. Raymond B. Cattell reduced Allport's extensive list to 16 fundamental groups of inter-related characteristics, and Hans Eysenck claimed that personality could be described based on three fundamental factors: psychoticism (such antisocial traits as cruelty and rejection of social customs), introversion-extroversion, and emotionality-stability (also called neuroticism). Eysenck also formulated a quadrant based on intersecting emotional-stable and introverted-extroverted axes.

Psychodynamic theory of personality

Twentieth-century views on personality have been heavily influenced by the psychodynamic approach of Sigmund Freud. Freud proposed a three-part personality structure consisting of the id (concerned with the gratification of basic instincts), the ego (which mediates between the demands of the id and the constraints of society), and the superego (through which parental and social values are internalized). In contrast to type or trait theories of personality, the dynamic model proposed by Freud involved an ongoing element of conflict, and it was these conflicts that Freud saw as the primary determinant of personality. His psychoanalytic method was designed to help patients resolve their conflicts by exploring unconscious thoughts, motivations, and conflicts through the use of free association and other techniques. Another distinctive feature of Freudian psychoanalysis is its emphasis on the importance of childhood experiences in personality formation. Other psychodynamic models were later developed by colleagues and followers of Freud, including Carl Jung, Alfred Adler, and Otto Rank (1884-1939), as well as other neo-Freudians such as Erich Fromm, Karen Horney, Harry Stack Sullivan (1892-1949), and Erik Erikson.

Phenomenological theory of personality

Another major view of personality developed during the twentieth century is the phenomenological approach, which emphasizes people's self-perceptions and their drive for self-actualization as determinants of personality. This optimistic orientation holds that people are innately inclined toward goodness, love, and creativity and that the primary natural motivation is the drive to fulfill one's potential. Carl Rogers, the figure whose name is most closely associated with phenomenological theories of personality, viewed authentic experience of one's self as the basic component of growth and wellbeing. This experience together with one's self-concept can become distorted when other people make the positive regard we need dependent on conditions that require the suppression of our true feelings. The client-centered therapy developed by Rogers relies on the therapist's continuous demonstration of empathy and unconditional positive regard to give clients the self-confidence to express and act on their true feelings and beliefs. Another prominent exponent of the phenomenological approach was Abraham Maslow, who placed self-actualization at the top of his hierarchy of human needs. Maslow focused on the need to replace a deficiency orientation, which consists of focusing on what one does not have, with a growth orientation based on satisfaction with one's identity and capabilities.

Behavioral theory of personality

The behaviorist approach views personality as a pattern of learned behaviors acquired through either classical (Pavlovian) or operant (Skinnerian) conditioning and shaped by reinforcement in the form of rewards or punishment. A relatively recent extension of behaviorism, the cognitive-behavioral approach emphasizes the role cognition plays in the learning process. Cognitive and social learning theorists focus not only on the outward behaviors people demonstrate but also on their expectations and their thoughts about others, themselves, and their own behavior. For example, one variable in the general theory of personality developed by social learning theorist Julian B. Rotter is internal-external orientation. "Internals" think of themselves as controlling events, while "externals" view events as largely outside their control. Like phenomenological theorists, those who take a social learning approach also emphasize people's perceptions of themselves and their abilities (a concept called "self-efficacy" by Albert Bandura). Another characteristic that sets the cognitive-behavioral approach apart from traditional forms of behaviorism is its focus on learning that takes place in social situations through observation and reinforcement, which contrasts with the dependence of classical and operant conditioning models on laboratory research.

Aside from theories about personality structure and dynamics, a major area of investigation in the study of personality is how it develops in the course of a person's lifetime. The Freudian approach includes an extensive description of psychosexual development from birth up to adulthood. Erik Erikson outlined eight stages of development spanning the entire human lifetime, from birth to death. In contrast, various other approaches, such as those of Jung, Adler, and Rogers, have rejected the notion of separate developmental stages.

An area of increasing interest is the study of how personality varies across cultures. In order to know whether observations about personality structure and formation reflect universal truths or merely cultural influences, it is necessary to study and compare personality characteristics in different societies. For example, significant differences have been found between personality development in the individualistic cultures of the West and in collectivist societies such as Japan, where children are taught from a young age that fitting in with the group takes precedence over the recognition of individual achievement. Cross-cultural differences may also be observed within a given society by studying the contrasts between its dominant culture and its subcultures (usually ethnic, racial, or religious groups).