psychology Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries betwe ...

, trait theory (also called dispositional theory) is an approach to the study of human

personality Personality is the characteristic sets of behaviors, cognitions, and emotional patterns that are formed from biological and environmental factors, and which change over time. While there is no generally agreed-upon definition of personality, mos ...

. Trait theorists are primarily interested in the measurement of ''traits'', which can be defined as habitual patterns of behaviour,

thought In their most common sense, the terms thought and thinking refer to conscious cognitive processes that can happen independently of sensory stimulation. Their most paradigmatic forms are judging, reasoning, concept formation, problem solving, a ...

, and

emotion Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. ...

. According to this perspective, traits are aspects of personality that are relatively stable over time, differ across individuals (e.g. some people are outgoing whereas others are not), are relatively consistent over situations, and influence behaviour. Traits are in contrast to

state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * ''The State'' (newspaper), a daily newspaper in Columbia, South Carolina, United States * ''Our S ...

s, which are more transitory dispositions. In some theories and systems, traits are something a person either has or does not have, but in many others traits are dimensions such as

extraversion vs. introversion The trait theory, traits of extraversion (also spelled extroversion Retrieved 2018-02-21.) and introversion are a central dimension in some human personality psychology, personality theories. The terms ''introversion'' and ''extraversion'' were ...

, with each person rating somewhere along this spectrum. There are two approaches to define traits: as internal causal properties or as purely descriptive summaries. The internal causal definition states that traits influence our behaviours, leading us to do things in line with that trait. On the other hand, traits as descriptive summaries are descriptions of our actions that don't try to infer causality.

History

Gordon Allport Gordon Willard Allport (November 11, 1897 – October 9, 1967) was an American psychologist. Allport was one of the first psychologists to focus on the study of the personality, and is often referred to as one of the founding figures of personali ...

was an early pioneer in the study of traits. This early work was viewed as the beginning of the modern psychological study of personality. He also referred to traits within his work as dispositions. In his approach, "cardinal" traits are those that dominate and shape a person's behavior; their ruling passions/obsessions, such as a need for money, fame etc. By contrast, "central" traits such as honesty are characteristics found in some degree in every person - and finally "secondary" traits are those seen only in certain circumstances (such as particular likes or dislikes that a very close friend may know), which are included to provide a complete picture of human complexity. A wide variety of alternative theories and scales were later developed, including: *

Raymond Cattell Raymond Bernard Cattell (20 March 1905 – 2 February 1998) was a British-American psychologist, known for his psychometric research into intrapersonal psychological structure.Gillis, J. (2014). ''Psychology's Secret Genius: The Lives and Works ...

's 16PF Questionnaire *

J. P. Guilford Joy Paul Guilford (March 7, 1897 – November 26, 1987) was an American psychologist best remembered for his psychometric study of human intelligence, including the distinction between convergent and divergent production. Developing the views ...

Structure of Intellect Joy Paul Guilford (March 7, 1897 – November 26, 1987) was an American psychologist best remembered for his psychometric study of human Intelligence (trait), intelligence, including the distinction between Convergent thinking, convergent and Div ...

Henry Murray Henry Alexander Murray (May 13, 1893 – June 23, 1988) was an American psychologist at Harvard University, where from 1959 to 1962 he conducted a series of psychologically damaging and purposefully abusive experiments on minors and under ...

's System of Needs *

Timothy Leary Timothy Francis Leary (October 22, 1920 – May 31, 1996) was an American psychologist and author known for his strong advocacy of psychedelic drugs. Evaluations of Leary are polarized, ranging from bold oracle to publicity hound. He was "a her ...

's Interpersonal circumplex *

Myers–Briggs Type Indicator In personality typology, the Myers–Briggs Type Indicator (MBTI) is an introspective self-report questionnaire indicating differing psychological preferences in how people perceive the world and make decisions. The test attempts to assign ...

Gray Grey (more common in British English) or gray (more common in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning literally that it is "without color", because it can be composed o ...

's Biopsychological theory of personality Currently, two general approaches are the most popular: *

Eysenck Personality Questionnaire In psychology, the Eysenck Personality Questionnaire (EPQ) is a questionnaire to assess the personality traits of a person. It was devised by psychologists Hans Jürgen Eysenck and Sybil B. G. Eysenck. Hans Eysenck's theory is based primarily on ...

, (EPQ) ("the three-factor model"). Using

factor analysis Factor analysis is a statistical method used to describe variability among observed, correlated variables in terms of a potentially lower number of unobserved variables called factors. For example, it is possible that variations in six observed ...

Hans Eysenck suggested that personality is reducible to three major traits:

neuroticism In the study of psychology, neuroticism has been considered a fundamental personality trait. For example, in the Big Five approach to personality trait theory, individuals with high scores for neuroticism are more likely than average to be moody ...

, extraversion, and psychoticism. *

Big Five personality traits The Big Five personality traits is a suggested taxonomy, or grouping, for personality traits, developed from the 1980s onward in psychological trait theory. Starting in the 1990s, the theory identified five factors by labels, for the US English ...

, ("the five-factor model"). Many psychologists currently believe that five factors are sufficient: neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness.

Trait theory in cross-cultural use

Cultures are widely known and accepted as being different in varying degrees. This can make the study of personality difficult as meaning and the expression of traits may be different within cultural groups. Trait theory uses a hierarchy of traits in order to separate culture from the traits; it can be said the culture is ignored in order to focus on the individual traits and how they are connected to the individual. Gordon Allport's trait theory not only served as a foundational approach within personality psychology, but also is continued to be viewed and discussed by other disciplines such as anthropology because of how he approached culture within trait theory. Trait theory tends to focus on the individual over the situation in which they are in. This focus has relaxed within modern studies allowing for a consideration of the external factors outside of the self. As the focus becomes more relaxed (but still prominent as it is a main part of the theory) research expands.

Comparing EPQ and Big Five

Testing methodology, and factors

Both the EPQ and Big Five approaches extensively use self-report questionnaires. The factors are intended to be

orthogonal In mathematics, orthogonality is the generalization of the geometric notion of ''perpendicularity''. By extension, orthogonality is also used to refer to the separation of specific features of a system. The term also has specialized meanings in ...

(uncorrelated), though there are often small positive

correlations In statistics, correlation or dependence is any statistical relationship, whether causal or not, between two random variables or bivariate data. Although in the broadest sense, "correlation" may indicate any type of association, in statistics ...

between factors. The five factor model in particular has been criticized for losing the orthogonal structure between factors. Hans Eysenck has argued that fewer factors are superior to a larger number of partly related ones. Although these two approaches are comparable because of the use of factor analysis to construct hierarchical taxonomies, they differ in the organization and number of factors. Whatever the causes,

psychoticism Psychoticism is one of the three traits used by the psychologist Hans Eysenck in his P–E–N model (psychoticism, extraversion and neuroticism) model of personality. Nature Psychoticism is conceptually similar to the ''constraint'' factor i ...

marks the two approaches apart, as the five factor model contains no such trait. Moreover, psychoticism, unlike any of the other factors in either approach, does not fit a normal distribution curve. Indeed, scores are rarely high, thus skewing a

normal distribution In statistics, a normal distribution or Gaussian distribution is a type of continuous probability distribution for a real-valued random variable. The general form of its probability density function is : f(x) = \frac e^ The parameter \mu ...

. However, when they are high, there is considerable overlap with psychiatric conditions such as

antisocial Antisocial may refer to: Sociology, psychiatry and psychology *Anti-social behaviour *Antisocial personality disorder *Psychopathy *Conduct disorder Law *Anti-social Behaviour Act 2003 *Anti-Social Behaviour Order *Crime and Disorder Act 1998 * ...

and

schizoid personality disorder Schizoid personality disorder (, often abbreviated as SzPD or ScPD) is a personality disorder characterized by a Asociality, lack of interest in social relationships, a tendency toward a solitary or sheltered lifestyle, secretiveness, emotion ...

s. Similarly, high scorers on

are more susceptible to

sleep Sleep is a sedentary state of mind and body. It is characterized by altered consciousness, relatively inhibited sensory activity, reduced muscle activity and reduced interactions with surroundings. It is distinguished from wakefulness by a de ...

and

psychosomatic A somatic symptom disorder, formerly known as a somatoform disorder,(2013) There are two higher-order factors that both taxonomies clearly share: extraversion and

. Both approaches broadly accept that extraversion is associated with

sociability Social behavior is behavior among two or more organisms within the same species, and encompasses any behavior in which one member affects the other. This is due to an interaction among those members. Social behavior can be seen as similar to an ...

and positive affect, whereas

is associated with emotional instability and negative affect. Matthews, G., Deary, I.J., & Whiteman, M.C. (2003). ''Personality traits'' (2nd edition). Cambridge: Cambridge University Press. Many lower-order factors, or

facets A facet is a flat surface of a geometric shape, e.g., of a cut gemstone. Facet may also refer to: Arts, entertainment, and media * ''Facets'' (album), an album by Jim Croce * ''Facets'', a 1980 album by jazz pianist Monty Alexander and his tri ...

, are similar between the two taxonomies. For instance, both approaches contain factors for sociability/gregariousness, for activity levels, and for assertiveness within the higher order factor extraversion. However, there are differences too. First, the three-factor approach contains nine lower-order factors and the five-factor approach has six. Eysenck's

factor incorporates some of the polar opposites of the lower order factors of openness, agreeableness and conscientiousness. A high scorer on tough-mindedness in

would score low on tender-mindedness in agreeableness. Most of the differences between the taxonomies stem from the three factor model's emphasis on fewer high-order factors.

Causality

Although both major trait models are descriptive, only the three-factor model offers a detailed causal explanation. Eysenck suggests that different personality traits are caused by the properties of the

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a v ...

, which themselves are the result of genetic factors. In particular, the three-factor model identifies the

reticular system The reticular formation is a set of interconnected Nucleus (neuroanatomy), nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of ...

and the

limbic system The limbic system, also known as the paleomammalian cortex, is a set of brain structures located on both sides of the thalamus, immediately beneath the medial temporal lobe of the cerebrum primarily in the forebrain.Schacter, Daniel L. 2012. ''Ps ...

in the brain as key components that mediate cortical arousal and emotional responses respectively. Eysenck advocates that extraverts have low levels of cortical arousal and introverts have high levels, leading extraverts to seek out more stimulation from socializing and being venturesome. Moreover, Eysenck surmised that there would be an optimal level of arousal, after which inhibition would occur and that this would be different for each person. In a similar vein, the three-factor approach theorizes that neuroticism is mediated by levels of arousal in the limbic system and that individual differences arise because of variable activation thresholds between people. Therefore, highly neurotic people when presented with minor stressors, will exceed this threshold, whereas people low in neuroticism will not exceed normal activation levels, even when presented with large stressors. By contrast, proponents of the five-factor approach assume a role of

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...

and environment but offer no explicit causal explanation. Given this emphasis on

biology Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary i ...

in the three-factor approach, it would be expected that the third trait, psychoticism, would have a similar explanation. However, the causal properties of this state are not well defined. Eysenck has suggested that psychoticism is related to

testosterone Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testes and prostate, as well as promoting secondar ...

levels and is an inverse function of the

serotonergic system Serotonin () or 5-hydroxytryptamine (5-HT) is a monoamine neurotransmitter. Its biological function is complex and multifaceted, modulating mood, cognition, reward, learning, memory, and numerous physiological processes such as vomiting and vas ...

, but he later revised this, linking it instead to the

dopaminergic system Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% o ...

List of personality traits

References

{{reflist, 30em Personality theories Personality traits