Personality

Personality

LEVELS OF PERSONALITY

PERSONALITY DEVELOPMENT AND CHANGE

BIOLOGICAL SUBSTRATES OF PERSONALITY

DISORDERED PERSONALITY

BIBLIOGRAPHY

Personality most commonly refers to the psychological features that distinguish one individual from another—regularities in the way an individual thinks, feels, and behaves. Although other characteristics may also distinguish individuals (for example, hair color, nationality, or job title), it is the psychological differences that fall under the umbrella of personality. These differences may be broad in nature, such as whether a person is outgoing or shy, emotional or calm, or they may be narrower in scope, reflecting finer grained patterns of beliefs, attitudes, and behaviors that may emerge only in certain situations. A person’s total collection of these characteristics defines his or her personality.

Personality also refers to a separate subfield of psychology that uses the scientific method to investigate people’s defining characteristics—what the characteristics are, how best to measure them, and the consequences for individuals who embody them. The young field of personality psychology was influenced by several early movements of the nineteenth century, starting with the European and North American philosophical tradition of individualism. Personality psychology emerged most prominently in the 1930s with the publication of the highly influential 1937 textbook Personality: A Psychological Interpretation, written by the psychologist Gordon Allport (1897–1967). The first personality inventory was conceived during World War I to predict who would be more emotionally fit for warfare. Since that time personality psychology has continued to emphasize sound measurement to capture a variety of aspects of human personality.

LEVELS OF PERSONALITY

Given the multitude of psychological differences among people, it is helpful to organize these differences into levels. For example, the psychologist Dan McAdams (b. 1954) has organized personality at three levels.

Traits At the broadest level, individuals differ in what are called dispositional traits. Traits outline the coarsest differences among people and reflect the most general and enduring orientations on the world.

Although different traits have been proposed throughout history, the earliest of which subdivided individuals into groups based on prominent bodily fluids or “humors” like blood (sanguine), yellow bile (choleric), black bile (melancholic), and phlegm (phlegmatic), in the early twenty-first century there appears to be some consensus on a trait taxonomy, commonly referred to as the “big five.” The big five personality traits are: extraversion (social, outgoing, energetic, and able to experience positive emotions), agreeableness (yields to and trusts others), conscientiousness (productive and follows through on tasks in an organized fashion), neuroticism (high anxiety, emotional instability, and hostility), and openness to experience (willingness to explore and engage in novel ideas, experiences, and feelings). These traits are continuous rather than categorical, with fewer people on the extremes and most people falling in between these extremes. Traits are controversial because they do not always predict how a person will behave or feel in a given situation because situations often constrain behavior. Instead, traits are more like statements about the probability that a person will behave in a certain way. Traits do predict important outcomes over longer periods of time, however. For example, extraversion predicts the time it takes people to develop a network of friends in a new environment. Likewise neuroticism is a risk factor for cardiac problems. Traits also have a strong genetic component, with evidence that about half of the variability in personality traits derive from genetic factors (that is, heritability quotients of 40 to 50 percent for most of the big five traits).

Consensus regarding the big five comes after decades of research, beginning in the 1930s with a painstaking search for terms in The Oxford English Dictionary that could be used to describe individuals. This task, undertaken by the prominent early personality theorists Gordon W. Allport and Henry S. Odbert, was guided by the principle that all of the important ways of characterizing people will be encoded in natural language use. Using this word list as a starting point, personality researchers like James Cattell and Hans Eysenck reduced the list into a smaller and more manageable number of categories using statistical techniques like factor analysis. In analysis after analysis, five personality dimensions consistently emerged, which came to be known as the big five. Other taxonomies have been proposed, for example, Eysenck focused on the big three, extraversion, neuroticism, and psychoticism (a combination of agreeableness and conscientiousness). Since the big five was developed, taxonomic analyses have yielded fairly good cross-cultural consistency in the five dimensions.

Other popularly known personality traits include type A and type B personalities. Type A individuals are typically driven, impatient, competitive, aggressive, and hostile, whereas type B individuals are the opposite—they are relaxed, patient, noncompetitive, and less hostile. The A/B distinction originated in the 1950s with a team of cardiologists who observed fast-paced aggressive behaviors in patients with coronary heart disease. Studies have subsequently confirmed type A as a cardiovascular risk factor—an association that appears driven by the hostility component and its negative physiological effects on blood pressure. Perhaps because of its intuitive appeal, “type A personality” moved into popular jargon fairly quickly. Fortunately the popular understanding of type A appears fairly true to the original concept.

Other related personalities include the controversial type C or “cancer prone” personality, which is characterized by emotion suppression. The associated type C coping style is characterized by denial of distress in spite of physiological evidence of distress. Evidence linking these characteristics to the incidence and recovery from cancer is mixed, however. Lastly, there is type D or distressed personality, characterized by negative emotionality, an inability to express emotions, and social isolation, which has been linked to greater cardiovascular disease and increased mortality.

Characteristics Adaptations At the next level of personality differences are mid-level characteristic adaptations, which comprise nuanced differences among people. Unlike traits, many of these adaptations are learned through experience, are readily influenced by culture, and reflect a dynamic interplay between people’s current contexts and situations. It is at this level that conditional theories of personality emerge as alternatives to trait theory.

One of the issues with defining personality solely as traits is that traits lead us to expect people will behave in a regular way across all situations. Yet empirical data do not show this. Typically the correlation between traits (as measured by standard trait questionnaires) and behaviors measured across situations is relatively modest—with correlations of .30. This observation, made by the personality psychologist Walter Mischel (b. 1930) in his influential 1968 text Personality and Assessment, sparked a decadeslong debate in personality known as the person-situation debate. This debate threatened the field of personality because it undermined the influence of personality traits on behavior and elevated the influence of situations on behavior, a perspective favored by social psychologists. One consequence of the debate is that it stimulated a more contextualized and conditional approach to personality, exemplified in Mischel’s research with his colleague, the psychologist Yuichi Shoda. From their perspective, personality emerges as situation-specific behavioral signatures —regularities in behavior that manifest in certain situations, not in all situations. Thus two people who are similar at the trait level (for example, high in neuroticism) may manifest different behavioral signatures. One person may react with hostility when confronted by authority, and another may react that way when confronted by a subordinate.

Central to a conditional approach to personality are people’s interpretations or construals of their immediate environments. This theme derives from a social-cognitive perspective on personality, which emphasizes the operation of acquired beliefs and expectations about the world in personality functioning. Within this social-cognitive perspective, there are several other types of individual differences that contribute to people’s behavioral signatures. Of particular importance are people’s beliefs regarding their self-efficacy, whether they believe they are capable of achieving desired outcomes through their actions. Formalized in theory by the psychologist Albert Bandura (b. 1925), self-efficacy beliefs are shaped from people’s experiences in the world and influence motivation, expectations, and the explanations people give for their outcomes. Self-efficacy and other human strengths, such as optimism, wisdom, and empathy, have received increased focus among personality and social psychologists. Also important are our implicit theories about the rigidity versus mutability of self-attributes. Some individuals, referred to as “entity theorists,” view their attributes, such as intelligence, as fixed and unchangeable, whereas others, “incremental theorists,” view their attributes as more malleable and able to be cultivated. These personal theories, which are heavily influenced by parenting, set up characteristic styles for how people approach and respond to challenging tasks, with incremental theorists being more likely to persist at tasks requiring effort.

Mid-level differences also include motives and drives. Within each culture, individuals differ in several higherorder motives —whether they are driven to achieve, affiliate with others, or have power over them. At the individual level, a person may also have his or her set of personal strivings —the idiosyncratic ways in which an individual tries to implement his or her goals in everyday life. For example, a person with strong affiliation motives might regularly get together with friends. A person with strong achievement motives might work long nights to achieve professional goals. Individuals may not always be aware of what motivates them. “Unconscious motives” are quite common and occur when a person regularly exhibits behaviors consistent with a motive but is unaware of having this motive. In these circumstances an external observer can often see these patterns more clearly than can the person.

Other mid-level aspects of personality, not just motives, can operate at an unconscious level. It is known that individuals possess considerable knowledge about themselves and their past experiences that they cannot verbalize or represent in consciousness but that shapes their feelings and behaviors. Such knowledge is often associative in nature and measured indirectly in ways that bypass self-report (for example, using computerized tasks adapted from cognitive psychology). This knowledge may be different from other reflective forms of self-knowledge that people can verbalize and report using questionnaires. Understanding the functions and interplay between associative and reflective components of personality appears to be among the major tasks of twenty-first-century science in personality. Another example of unconscious personality processes is found in defense mechanisms, which reflect patterns of thinking that minimize conscious awareness of threatening thoughts or feelings. With repeated and frequent use, defense mechanisms can become part of a person’s characteristic style of thinking.

Personal Narratives In addition to traits and characteristic adaptations, individuals differ in their integrative life narratives. Life narratives are the unique person-specific stories people create about their experiences to provide coherence and meaning to their lives. A life story encompasses who a person is, how this person came to be, and what the future holds. Although each story is unique, common themes do emerge—despair, resurrection, and triumph—that are often culturally bound. Narratives also have important psychological consequences, as evidence suggests that writing about a traumatic experience in a way that gives the experience coherence and meaning speeds recovery and improves mental and physical health.

PERSONALITY DEVELOPMENT AND CHANGE

Change depends on whether personality is conceived of as traits, characteristic adaptations, or life narratives. Traits exhibit the most stability and are the hardest to change, which is consistent with traits being partly heritable and rooted in infant temperament. Early learning environments can play some role in shaping the expression of traits, however. For example, temperamentally introverted children who are exposed to intensive social environments early in life, such as day care, evidence less introversion later in life, but they may never be as outgoing as children who exhibited extraverted behaviors prior to socialization.

Traits crystallize between ages twenty-one to thirty, after which they show consistency through older adulthood. Of course people are dynamic, and they can change across their lifetime. Such changes, however, appear to occur at the level of characteristic adaptations and life narratives. Indeed therapy is often targeted at changing people’s beliefs, motivations, coping strategies, and life stories rather than changing enduring dispositions. Personality also changes through adult maturational stages characterized by decreasing impulsivity, maturing defenses, changing identities (for example, parenthood), and a shift in orientation from self to other.

BIOLOGICAL SUBSTRATES OF PERSONALITY

Personality psychologists have begun to understand the neurobiological underpinnings of traits such as extraversion and neuroticism. For example, extraversion and its associated qualities of impulsivity and sensation seeking appear most strongly linked to the behavioral activation system (BAS), which consists of dopamine-transmitting pathways in the brain and neural structures that modulate the extent to which people feel pleasure in response to cues for reward. By contrast, neuroticism appears most strongly linked to the behavioral inhibition system (BIS), a set of neural structures and processes involved in anxiety and the processing of aversive outcomes such as punishment.

New avenues of research in molecular genetics hold promise for investigating links between genes and personality. For example, emergent research suggests that variation in a gene related to dopamine function (DRD4) is associated with personality differences in novelty seeking, just as variation in a gene related to serotonin function (5-HT transporter) has been linked to differences in neuroticism. The mechanisms of action between genes and personality are complex and not yet known, however. Research in genetics will likely yield important advancements in the years to come, particularly with respect to multiple gene contributions to personality, mechanisms of action, and gene-environment interplay.

DISORDERED PERSONALITY

Personality disorders appear to represent the extremes of normal variation in broad personality traits. Many of the personality disorders described in the 2000 Diagnostic and Statistical Manual of Mental Disorders, fourth edition text revision (DSM-IV-TR), correspond to extreme variants of the big five personality factors. For example, borderline personality disorder—characterized by impulsivity, self-destructive behavior, and emotional instability—may be a maladaptive form of the anger and hostility subfacets of neuroticism; obsessive-compulsive disorder may be related to extreme conscientiousness, with an extreme focus on order, perfectionism, rules, and structure; and paranoid personality disorder may be related to extremely low agreeableness, reflecting a wariness and mistrust of others.

SEE ALSO Allport, Gordon; Bandura, Albert; Individualism; Mental Illness; Neuroscience; Obsessive-Compulsive Disorder; Optimism/Pessimism; Psychology; Self-Defeating Behavior; Self-Efficacy; Temperament; Trait Theory

BIBLIOGRAPHY

American Psychiatric Association. 2000. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association.

Canli, Turhan, ed. 2006. Biology of Personality and Individual Differences. New York: Guilford.

Epstein, Seymour, and Edward J. O’Brien. 1985. The Person-Situation Debate in Historical and Current Perspective. Psychological Bulletin 98 (3): 513–537.

Funder, David C. 2001. Personality. Annual Review of Psychology 52: 197–221.

Heatherton, Todd F., and Joel L. Weinberger, eds. 1994. Can Personality Change? Washington, DC: American Psychological Association.

McAdams, Dan P. 2006. The Person: A New Introduction to Personality Psychology. 4th ed. Hoboken, NJ: Wiley.

McCrae, Robert R., and Paul T. Costa Jr. 1997. Personality Trait Structure as a Human Universal. American Psychologist 52 (5): 509–516.

Mischel, Walter, and Yuichi Shoda. 1995. A Cognitive-Affective System Theory of Personality: Reconceptualizing Situations, Dispositions, Dynamics, and Invariance in Personality Structure. Psychological Review 102 (2): 246–268.

Pervin, Lawrence A., and Oliver P. John, eds. 1999. Handbook of Personality: Theory and Research. 2nd ed. New York: Guilford.

Wilson, Timothy D. 2002. Strangers to Ourselves: Discovering the Adaptive Unconscious. Cambridge, MA: Belknap Press of Harvard University.

Tamlin S. Conner

Howard Tennen