Personality

In psychology, personality is a description of consistent emotional, thought, and behavior patterns in a person.

Personality psychology is a branch of psychology which studies personality and individual differences. One emphasis in this area is to construct a coherent picture of a person and his or her major psychological processes. Another emphasis views personality as the study of individual differences, in other words, how people differ from each other. A third area of emphasis examines human nature and how all people are similar to one other. These three viewpoints merge together in the study of personality.

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 (Ryckman, 2004). The word "personality" originates from the greek 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.

The pioneering American psychologist, Gordon Allport (1937) described two major ways to study personality, the nomothetic and the idiographic. Nomothetic psychology seeks general laws that can be applied to many different people, such as the principle of self-actualization, or the trait of extraversion. Idiographic psychology is an attempt to understand the unique aspects of a particular individual.

The study of personality has a rich and varied history in psychology, with an abundance of theoretical traditions. Some psychologists have taken a highly scientific approach, whereas others have focused their attention on theory development.

Critics of personality theory claim that personality is "plastic" across time, places, moods, and situations. Changes in personality may indeed result from diet (or lack thereof), medical effects, significant events, or learning. However, most personality theories emphasize stability over fluctuation.

Trait theories

According to the Diagnostic and Statistical Manual of the American Psychiatric Association, personality traits are "enduring patterns of perceiving, relating to, and thinking about the environment and oneself that are exhibited in a wide range of social and personal contexts." Theorists generally assume that a) traits are relatively stable over time, b) traits differ among individuals (e.g. some people are outgoing while others are shy), and c) traits influence behavior.

The most common models of traits incorporate three to five broad dimensions or factors. The least controversial dimension, observed as far back as the ancient Greeks, is simply extraversion vs. introversion (outgoing and physical-stimulation-oriented vs. quiet and physical-stimulation-averse).

• Gordon Allport delineated different kinds of traits, which he also called dispositions. Central traits are basic to an individual's personality, while secondary traits are more peripheral. Common traits are those recognized within a culture and thus may vary from culture to culture. Cardinal traits are those by which an individual may be strongly recognized.

• Raymond Cattell's research propagated a two-tiered personality structure with sixteen "primary factors" (16 Personality Factors) and five "secondary factors." A different model was proposed by Hans Eysenck, who believed that just three traits - extraversion, neuroticism and psychoticism - were sufficient to describe human personality. Differences between Cattell and Eysenck emerged due to preferences for different forms of factor analysis, with Cattell using oblique, Eysenck orthogonal, rotation to analyse the factors that emerged when personality questionnaires were subjected to statistical analysis. Today, the Big Five factors have the weight of a considerable amount of empirical research behind them. Building on the work of Cattell and others, Lewis Goldberg proposed a five-dimension personality model, nicknamed the "Big Five":

1. Extraversion - outgoing and stimulation-oriented vs. quiet and stimulation-avoiding
2. Neuroticism - emotionally reactive, prone to negative emotions vs. calm, imperturbable, optimistic
3. Agreeableness - affable, friendly, conciliatory vs. aggressive, dominant, disagreeable
4. Conscientiousness - dutiful, planful, and orderly vs. laidback, spontaneous, and unreliable
5. Openness to experience - open to new ideas and change vs. traditional and oriented toward routine

For ease of remembrance this can be written as OCEAN

• John L. Holland's RIASEC vocational model, commonly referred to as the Holland Codes, stipulates that there are six personality traits that lead people to choose their career paths. This model is widely used in vocational counseling and is a circumplex model where the six types are represented as a hexagon where adjacent types are more closely related than those more distant.

Trait models have been criticized as being purely descriptive and offering little explanation of the underlying causes of personality. Eysenck's theory, however, does propose biological mechanisms as driving traits, and modern behavior genetics researchers have demonstrated a clear genetic substrate to them. Another potential weakness with trait theories is that they lead people to accept oversimplified classifications, or worse offer advice, based on a superficial analysis of one's personality. Finally, trait models often underestimate the effect of specific situations on people's behavior. It is important to remember that traits are statistical generalizations that do not always correspond to an individual's behavior.

Type theories

Personality type refers to the psychological classification of different types of people. Personality types are distinguished from personality traits, which come in different levels or degrees. According to type theories, for example, there are two types of people, introverts and extraverts. According to trait theories, introversion and extraversion are ends of a continuous spectrum, with many people in the middle. The idea of psychological types originated in the theoretical work of Carl Jung.

Psychoanalytic theories

Psychoanalytic theories explain human behaviour in terms of the interaction of various components of personality. Sigmund Freud was the founder of this school. Freud drew on the physics of his day (thermodynamics) to coin the term psychodynamics. Based on the idea of converting heat into mechanical energy, he proposed that psychic energy could be converted into behavior. Freud's theory places central importance on dynamic, unconscious psychological conflicts.

Behaviorist theories

Behaviorists explain personality in terms of reactions to external stimuli, and was a radical shift away from Freudian philosophy. This school of thought was developed by B. F. Skinner who put forth a model which emphasized the mutual interaction of the person or "the organism" with its environment. Skinner believed that children do bad things in order to get the attention that they crave. For example: a child cries because the child desires attention and knows it will be given. These are the stimulus, response, and consequences. The stimulus is the child being ignored, the response is the child acting out, and the attention that child gets is the consequence. According to this theory, people's behavior is formed by processes such as operant conditioning. Skinner put forward a 'three term contingency model' which helped promote analysis of behavior based on the 'Stimulus - Response - Consequence Model' in which the critical question is: "Under which circumstances or antecedent "stimuli" does the organism engage in a particular behavior or "response," which in turn produces a particular "consequence"?"

Ivan Pavlov is another notable influence. He is well known for his classical conditions experiments involving a dog. These physiological studies on this dog led him to discover the foundation of behaviorism as well as classical conditioning. Pavlov would begin his experiment by first ringing a bell, which would cause no response from the dog. He would proceed to place food in front of the dog's face, causing the dog to salivate. Several seconds later, he would ring the bell again, causing the dog to now salivate. After continuing this experiment several times, the dog would salivate at just the ring of the bell. These conditioning experiments can be used for many different types of experiments. He can do these experiments for any situation. For example, If every time someone ate fish they got sick, and he rang the bell when they ate the fish, eventually they would get sick from just the sound of the bell.

John B. Watson, The Father of American Behaviorism, made four major assumptions about radical Behaviorisms -

1. Evolutionary Continuity: The laws of behavior are applied equally to all living organisms, so we can study animals as simple models of complex human responses.
2. Reductionism: All behaviors are linked to physiology.
3. Determinism: Animals do not respond freely, they respond in a programmed way to external stimuli. Biological organisms respond to outside influences.
4. Empiricism: Only our actions are observable evidence of our personality. Psychology should involve the study of observable (overt) behavior.

All behaviorists focus on observable behavior. Thus there is no emphasis on unconscious motives, internal traits, introspection, or self analysis. Behavior modification is a form of therapy that applies the principles of learning to achieve changes in behavior.

Cognitive theories

In cognitivism, behavior is explained as guided by cognitions (e.g. expectations) about the world, especially those about other people. Cognitive theories are theories of personality that emphasize cognitive processes such as thinking and judging.

Albert Bandura, a social learning theorist suggested that the forces of memory and emotions worked in conjunction with environmental influences. Bandura was known mostly for his studies involving his "bobo doll." During these experiments, Bandura video taped a college student kicking and verbally abusing a bobo doll. He then showed this video to a class of kindergartners who were getting ready to go out to play. When they entered the play room, they saw bobo dolls, and some hammers. The people observing these children at play saw a group of children beating the doll. He called this study and his findings observational learning, or modeling.

Early examples of approaches to cognitive style are listed by Baron (1982). These include Witkin's (1965) work on field dependency, Gardner's (1953) discovering people had consistent preference for the number of categories they used to categorise heterogeneous objects, and Block and Petersen's (1955) work on confidence in line discrimination judgments. More central to this field have been:

1. Self-efficacy work, dealing with confidence people have in abilities to do tasks (Bandura, 1997);
2. Locus of control theory (Lefcourt, 1966; Rotter, 1966) dealing with different beliefs people have about whether their worlds are controlled by themselves or external factors;
3. Attributional style theory (Abramson, Seligman and Teasdale, 1978) dealing with different ways in which people explain events in their lives. This approach builds upon locus of control, but extends it by stating that we also need to consider whether people attribute to stable causes or variable causes, and to global causes or specific causes.

Humanistic theories

In humanistic psychology it is emphasized that people have free will and that they play an active role in determining how they behave. Accordingly, humanistic psychology focuses on subjective experiences of persons as opposed to forced, definitive factors that determine behaviour. Abraham Maslow and Carl Rogers were proponents of this view.

Maslow and Rogers emphasized a view of the person as an active, creative, experiencing human being who lives in the present and subjectively responds to current perceptions, relationships, and encounters. They disagree with the dark, pessimistic outlook of those in the Freudian psychoanalysis ranks, but rather view humanistic theories as positive and optimistic proposals which stress the tendency of the human personality toward growth and self-actualization. This progressing self will remain the center of its constantly changing world; a world that will help mold the self but not necessarily confine it. Rather, the self has opportunity for maturation based on its encounters with this world. This understanding attempts to reduce the acceptance of hopeless redundancy. Humanistic therapy typically relies on the client for information of the past and its effect on the present, therefore the client dictates the type of guidance the therapist may initiate. This allows for an individualized approach to therapy.Rogers found that patients differ in how they respond to other people. Rogers tried to model a particular approach to therapy- he stressed the response. These responses came in a variety of fashions:

A. Evaluative Response – Place a value judgment on person’s feelings B. Interpretive Response- tells the person what they’re really thinking or feeling. C. Reflective Response- Captures how someone is feeling right now about the situation.

Biopsychological theories

Around the 1990s, neuroscience entered the domain of personality psychology. Whereas previous efforts for identifying personality differences relied upon simple, direct, human observation, neuroscience introduced powerful brain analysis tools like Electroencephalography (EEG), Positron Emission Tomography (PET), and Functional Magnetic Resonance Imaging (fMRI) to this study. One of the founders of this area of brain research is Richard Davidson of the University of Wisconsin-Madison. Davidson's research lab has focussed on the role of the prefrontal cortex (PFC) and amygdala in manifesting human personality. In particular, this research has looked at hemispheric asymmetry of activity in these regions. Neuropsychological studies have illustrated how hemispheric asymmetry can affect an individual's personality (particularly in social settings) for individuals who have NLD (non-verbal learning disorder) which is marked by the impairment of nonverbal information controlled by the right hemisphere of the brain. Difficulties will arise in the areas of gross motor skills, inability to organize visual-spatial relations, or adapt to novel social situations. Frequently, a person with NLD is unable to interpret non-verbal cues, and therefore experiences difficulty interacting with peers in socially normative ways.