In psychology, trait theory (also called dispositional theory) is an approach to the study of human personality. Trait theorists are primarily interested in the measurement of traits, which can be defined as habitual patterns of behavior, thought, and emotion. According to this perspective, traits are relatively stable over time, differ across individuals (e.g. some people are outgoing whereas others are shy), and influence behavior. Traits are in contrast to states which are more transitory dispositions.
Gordon Allport was an early pioneer in the study of traits, which he sometimes referred to as dispositions. In his approach, central traits are basic to an individual's personality, whereas secondary traits are more peripheral. Common traits are those recognized within a culture and may vary between cultures. Cardinal traits are those by which an individual may be strongly recognized. Since Allport's time, trait theorists have focused more on group statistics than on single individuals. Allport called these two emphases "nomothetic" and "idiographic," respectively.
There are nearly unlimited number of potential traits that could be used to describe personality. The statistical technique of factor analysis, however, has demonstrated that particular clusters of traits reliably correlate together. Hans Eysenck has suggested that personality is reducible to three major traits: neuroticism, extroversion, and psychoticism . Other researchers argue that more factors are needed to adequately describe human personality including humor, wealth and beauty. Many psychologists currently believe that five factors are sufficient. These "big five" personality traits are neuroticism, extraversion, openness to experience, agreeableness, and conscientiousness. These are actually continuums and each factor will also vary by intensity.
Virtually all trait models, and even ancient Greek philosophy, include extraversion vs. introversion as a central dimension of human personality. Another prominent trait that is found in nearly all models is Neuroticism, or emotional instability.
The two taxonomies
Both approaches extensively use self-report questionnaires. The factors are intended to be orthogonal (uncorrelated), though there are often small positive correlations 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, however, psychoticism 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. However, when they are high, there is considerable overlap with psychiatric conditions such as antisocial and schizoid personality disorders. Similarly, high scorers on neuroticism are more susceptible to sleep and psychosomatic disorders. Five factor approaches can also predict future mental disorders.
There are two higher-order factors that both taxonomies clearly share: extraversion and neuroticism. Both approaches broadly accept that extraversion is associated with sociability and positive affect, whereas neuroticism is associated with emotional instability and negative affect.
Many lower-order factors, or facets, 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 psychoticism factor incorporates some of the polar opposites of the lower order factors of openness, agreeableness and conscientiousness. A high scorer on tough-mindedness in psychoticism 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.
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, which themselves are the result of genetic factors. In particular, the three-factor model identifies the reticular system and the limbic system 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  and environment  but offer no explicit causal explanation.
Given this emphasis on biology 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 levels and is an inverse function of the serotonergic system, but he later revised this, linking it instead to the dopaminergic system.
List of personality traits
|Openness to experience||Composed of two related but separable traits, Openness to Experience and Intellect. Behavioral aspects include having wide interests, and being imaginative and insightful, correlated with activity in the dorsolateral prefrontal cortex. Considered primarily a cognitive trait.|
|Conscientiousness||Scrupulous, meticulous, principled behavior guided or conforming to one's own conscience. Associated with the dorsolateral prefrontal cortex. Anorexics are noted to have higher levels of conscientiousness.|
|Extraversion||Gregarious, outgoing, sociable, projecting one's personality outward. The opposite of extraversion is introversion. Extraversion has shown to share certain genetic markers with substance abuse. Extraversion is associated with various regions of the prefrontal cortex and the amygdala.|
|Agreeableness||Refers to a compliant, trusting, empathic, sympathetic, friendly and cooperative nature.|
|Neuroticism||"Refers to an individual's tendency to become upset or emotional" (Hans Eysenck) "Neuroticism is the major factor of personality pathology" (Eysenck & Eysenck, 1969). Neuroticism has been linked to serotonin transporter (5-HTT) binding sites in the thalamus: as well as activity in the insular cortex. Neuroticism also predicts the occurrence of more negative life experiences.|
|Self-esteem (low)||A "favorable or unfavorable attitude toward the self" (Rosenberg, 1965). An individual's sense of his or her value or worth, or the extent to which a person values, approves of, appreciates, prizes, or likes him or herself" (Blascovich & Tomaka, 1991).|
|Harm avoidance||A tendency towards shyness, being fearful and uncertain, tendency to worry. Neonatal complications such as preterm birth have been shown to affect harm avoidance. People affected by eating disorders exhibit high levels of harm avoidance. The volume of the left amygdala in girls was correlated to levels of HA, in separate studies HA was correlated with reduced grey matter volume in the orbito-frontal, occipital and parietal regions.|
|Novelty seeking||Impulsive, exploratory, fickle, excitable, quick-tempered, and extravagant. Associated with addictive behavior.|
|Perfectionism||"I don't think needing to be perfect is in any way adaptive" (Paul Hewitt, PhD)
Socially prescribed perfectionism – "believing that others will value you only if you are perfect."
Self-oriented perfectionism – "an internally motivated desire to be perfect.
|Alexithymia||The inability to express emotions. "To have no words for one's inner experience" (Rený J. Muller PhD). In studies done with stroke patients, alexithymia was found to be more prevalent in those who developed lesions in the right hemisphere following a cerebral infarction. There is a positive association with post-traumatic stress disorder (PTSD), childhood abuse and neglect and alexithymia. Utilizing psychometric testing and fMRI, studies showed positive response in the insula, posterior cingulate cortex (PCC), and thalamus.|
|Rigidity||Inflexibility, difficulty making transitions, adherence to set patterns. Mental rigidity arises out of a deficit of the executive functions. Originally termed frontal lobe syndrome it is also referred to as dysexecutive syndrome and usually occurs as a result of damage to the frontal lobe. This may be due to physical damage, disease (such as Huntington's disease) or a hypoxic or anoxic insult.|
|Impulsivity||Risk taking, lack of planning, and making up one's mind quickly (Eysenck and Eysenck). A component of disinhibition. Abnormal patterns of impulsivity have been linked to lesions in the right inferior frontal gyrus and in studies done by Antonio Damasio author of Descartes Error, damage to the ventromedial prefrontal cortex has been shown to cause a defect in real-life decision making in individuals with otherwise normal intellect. Those who sustain this type of damage are oblivious to the future consequences of their actions and live in the here and now.|
|Disinhibition||Behavioral dis-inhibition is an inability or unwillingness to constrain impulses, it is a key component of executive functioning. Researchers have emphasized poor behavioral inhibition as the central impairment of ADHD. It may be symptomatic of orbitofrontal lobe syndrome, a subtype of frontal lobe syndrome which may be an acquired disorder as a result of traumatic brain injury, hypoxic ischemic encephalopathy (HIE), anoxic encephalopathy, degenerative diseases such as Parkinson's, bacterial or viral infections such as Lyme disease and neurosyphilis. Disinhibition has been consistently associated with substance abuse disorders, obesity, higher BMI, excessive eating, an increased rate of eating, and perceived hunger.|
|Psychoticism||Psychoticism is a personality pattern typified by aggressiveness and interpersonal hostility, one of four traits in Hans Eysenck's model of personality. High levels of this trait were believed by Eysenck to be linked to increased vulnerability to psychosis such as schizophrenia. He also believed that blood relatives of psychotics would show high levels of this trait, suggesting a genetic basis to the trait.|
|Obsessionality||Persistent, often unwelcome, and frequently disturbing ideas, thoughts, images or emotions, rumination, often inducing an anxious state. Obsessionality may result as a dysfunction of the basal ganglia.|
- 16 Personality Factors
- Big Five personality traits
- Hans Eysenck
- HEXACO model of personality structure
- Personality psychology
- Alternative five model of personality
- Cultural schema theory
- Szondi test
- Saul Kassin, (2003). Psychology. USA: Prentice-Hall, Inc.
- Hans Eysenck, (1967). The biological basis of personality. Springfield, IL: Thomas.
- Hans Eysenck, (1991). Dimensions of personality: 16: 5 or 3? Criteria for a taxonomic paradigm. Personality and Individual Differences, 12, 773–790.
- Saucier, G., & Goldberg, L. R. (1998). What is beyond the Big Five? Journal of Personality, 66, 495–524.
- McCrae, R. R., & Costa, P. C., Jr. (1987). Validation of the five-factor model across instruments and observers. Journal of Personality and Social Psychology, 52, 81–90.
- Costa, P. T., & McCrae, R. R. (1992). Four ways five factors are basic. Personality and Individual Differences, 13, 653–665.
- Hans Eysenck, (1990). Biological dimensions of personality. In L. A. Pervin (Ed.), Handbook of personality: Theory and research (pp. 244–276). New York: Guilford.
- Block, J. (1995). A contrarian view of the five-factor approach to personality description. Psychological Bulletin, 117, 187–215.
- Draycott, S. G., & Kline, P. (1995). The Big Three or the Big Five - the EPQ-R vs the NEO-PI: a research note, replication and elaboration. Personality and Individual Differences, 18, 801–804.
- Eysenck, H. J. (1992). A reply to Costa and McCrae. P or A and C: The role of theory. Personality and Individual Differences, 13, 867–868.
- Matthews, G., Deary, I.J., & Whiteman, M.C. (2003). Personality traits (2nd edition). Cambridge: Cambridge University Press.
- Hans Eysenck and S. B. G. Eysenck. (1991). The Eysenck Personality Questionnaire-Revised. Sevenoaks: Hodder & Stoughton.
- Costa, P. T., & McCrae, R. R. (1990). Personality disorders and the five factor model of personality. Journal of Personality Disorders, 4, 362–371.
- Lynam, D. R., Caspi, A., Moffitt, T. E., Raine, A., Loeber, R., & Stouthamer-Loeber, M. (2005). Adolescent psychopathy and the Big Five: Results from two samples. Journal of Abnormal Child Psychology, 33, 431–443.
- Eysenck, H. J., & Eysenck, M. W. (1985). Personality and individual differences: A natural science approach. New York: Plenum.
- Eysenck, H.J. (1967). The biological basis of personality. Springfield, IL: Thomas.
- Eysenck, H. J. (1994). Creativity and personality: Word association, origence, and Psychoticism. Creativity Research Journal, 7, 209–216.
- Jeronimus, B.F.; Riese, H.; Sanderman, R.; Ormel, J. (2014). "Mutual Reinforcement Between Neuroticism and Life Experiences: A Five-Wave, 16-Year Study to Test Reciprocal Causation". Journal of Personality and Social Psychology 107 (4): 751–64.
- Eysenck, H. J. (1992). The definition and measurement of psychoticism. Personality and Individual Differences, 13, 757–785.
- Eysenck, H. J. (1997). Personality and experimental psychology: The unification of psychology and the possibility of a paradigm. Journal of Personality and Social Psychology, 73, 1224–1237.
- DeYoung CG, Peterson JB, Higgins DM.J Pers. Sources of openness/intellect: cognitive and neuropsychological correlates of the fifth factor of personality.2005 Aug;73(4):825-58. doi:10.1111/j.1467-6494.2005.00330.x PMID 15958136
- MacLaren VV, Best LA.Female students' disordered eating and the big five personality facets. Eat Behav. 2009 Aug;10(3):192-5. Epub 2009 Apr 17.PMID 19665103
- Heaven PC, Mulligan K, Merrilees R, Woods T, Fairooz Y. Neuroticism and conscientiousness as predictors of emotional, external, and restrained eating behaviors. Int J Eat Disord. 2001 Sep;30(2):161-6.PMID 11449449
- Casper RC, Hedeker D, McClough JF. Personality dimensions in eating disorders and their relevance for subtyping. J Am Acad Child Adolesc Psychiatry. 1992 Sep;31(5):830-40.PMID 1400113
- Luo X, Kranzler HR, Zuo L, Wang S, Gelernter J. Personality Traits of Agreeableness and Extraversion are Associated with ADH4 VariationBiol Psychiatry. 2007 Mar 1;61(5):599–608. Epub 2006 Oct 25. doi:10.1016/j.biopsych.2006.05.017 PMID 17069770
- Wright CI. et al. Neuroanatomical correlates of extraversion and neuroticism. Cereb Cortex. 2006 Dec;16(12):1809–19. Epub 2006 Jan 18.PMID 16421327
- Mendez MF, Chen AK, Shapira JS, Lu PH, Miller BL.Acquired extroversion associated with bitemporal variant of frontotemporal dementia. J Neuropsychiatry Clin Neurosci. 2006 Winter;18(1):100-7.PMID 16525077
- Rankin KP. et al. Right and left medial orbitofrontal volumes show an opposite relationship to agreeableness in FTD. Dement Geriatr Cogn Disord. 2004;17(4):328-32.PMID 15178947
- Graziano WG, Tobin RM.Agreeableness: dimension of personality or social desirability artifact? Bergeman CS et al. Genetic and environmental effects on openness to experience, agreeableness, and conscientiousness: an adoption/twin study. J Pers. 1993 Jun;61(2):159-79.PMID 8345444
- J Pers. 2002 Oct;70(5):695–727. PMID 12322857
- Miller JL et al. Neuroticism and introversion: a risky combination for disordered eating among a non-clinical sample of undergraduate women. Eat Behav. 2006 Jan;7(1):69–78. Epub 2005 Aug 1. PMID 16360625
- Takano A, et al. Relationship between neuroticism personality trait and serotonin transporter binding. Biol Psychiatry. 2007 Sep 15;62(6):588-92. Epub 2007 Mar 6. doi:10.1016/j.biopsych.2006.11.007 PMID 17336939
- Deckersbach T, et al. Regional cerebral brain metabolism correlates of neuroticism and extraversion. Depress Anxiety. 2006;23(3):133-8. PMID 16470804
- Button EJ Self-esteem, eating problems and psychological wellbeing in a cohort of school age 15–16: question and interview PMID 8986516Int J Eat Disord 1997 Jan;21(1):39–41
- Strober M.,Personality factors in anorexia nervosa.,Pediatrician. 1983–1985;12(2–3):134-8. PMID 6400211
- Eiber R et al. Self-esteem: a comparison study between eating disorders and social phobia. Encephale. 2003 Jan–Feb; 29(1):35–41. PMID 12640325
- Bulik, C. M. et al, Eating disorders and antecedent anxiety disorders: a controlled study Acta Psychiatrica Scandinavica Volume 96, Issue 2, pages 101–107, August 1997doi:10.1111/j.1600-0447.1997.tb09913.x
- Favaro A, Tenconi E, Santonastaso P. The relationship between obstetric complications and temperament in eating disorders: a mediation hypothesis. Psychosom Med. 2008 Apr;70(3):372-7. Epub 2008 Feb 6. doi:10.1097/PSY.0b013e318164604e PMID 18256341
- Iidaka T. et al. Volume of left amygdala subregion predicted temperamental trait of harm avoidance in female young subjects. A voxel-based morphometry study. Brain Res. 2006 Dec 13; 1125(1):85–93. Epub 2006 Nov 17.PMID 17113049
- Peterson CB. Personality dimensions in bulimia nervosa, binge eating disorder, and obesity. Compr Psychiatry. 2010 Jan–Feb; 51(1):31-6. Epub 2009 May 2. PMID 19932823
- Gardini S, Cloninger CR, Venneri A. Individual differences in personality traits reflect structural variance in specific brain regions. Brain Res Bull. 2009 Jun 30; 79(5):265-70. Epub 2009 Mar 28. PMID 19480986
- Halmi KA et al. Perfectionism in anorexia nervosa: variation by clinical subtype, obsessionality, and pathological eating behavior. Am J Psychiatry. 2000 Nov;157(11):1799-805. PMID 11058477
- Ruggiero GM. et al. Stress situation reveals an association between perfectionism and drive for thinness. Int J Eat Disord. 2003 Sep;34(2):220-6. PMID 12898558
- Hewitt PL et al. "The impact of perfectionistic self-presentation on the cognitive, affective, and physiological experience of a clinical interview Psychiatry. 2008 Summer;71(2):93–122. PMID 18573033
- Frewen PA, Pain C, Dozois DJ, Lanius RA. Alexithymia in PTSD: psychometric and FMRI studies. Ann N Y Acad Sci. 2006 Jul;1071:397–400.PMID 16891585
- O Guilbaud et al. Alexithymia and depression in eating disorders Encephale. 2000 Sep–Oct(5);1–6 PMID 11192799
- Smith GJ et al. Alexithymia in patients with eating disorders: an investigation using a new projective technique. Percept Mot Skills. 1997 Aug; 85(1):247-56. PMID 9293583
- Peskine A, Picq C, Pradat-Diehl P.Brain Inj. Cerebral anoxia and disability. 2004 Dec;18(12):1243–54.PMID 15666568
- Ho AK, Robbins AO, Barker RAHuntington's disease patients have selective problems with insightMov Disord. 2006 Mar;21(3):385-9. PMID 16211608
- Tchanturia K et al. Perceptual illusions in eating disorders: rigid and fluctuating styles Behav Ther Exp Psychiatry. 2001 Sep;32(3):107-15. PMID 11934124
- Cserjési R.Affect, cognition, awareness and behavior in eating disorders. Comparison between obesity and anorexia nervosa. Orv Hetil. 2009 Jun 1;150(24):1135–43. PMID 19482720
- Bechara A, Damasio AR, Damasio H, Anderson SW. Insensitivity to future consequences following damage to human prefrontal cortex. Cognition. 1994 Apr–Jun; 50(1–3):7–15.PMID 8039375
- Eysenck SB, Eysenck HJ. The place of impulsiveness in a dimensional system of personality description Br J Soc Clin Psychol. 1977 Feb;16(1):57–68. PMID 843784
- Welch SL, Fairburn CG. Impulsivity or comorbidity in bulimia nervosa. A controlled study of deliberate self-harm and alcohol and drug misuse in a community sample. Br J Psychiatry. 1996 Oct;169(4):451-8. PMID 8894196
- Corstorphine E et al. Trauma and multi-impulsivity in the eating disorders. Eat Behav. 2007 Jan;8(1):23–30. Epub 2004 Sep 22. PMID 17174848
- Patton JH, Stanford MS, Barratt ES. J Clin Psychol. 1995 Nov;51(6):768-74. Factor structure of the Barratt impulsiveness scale. PMID 8778124
- Chamberlain SR, Sahakian BJ. The neuropsychiatry of impulsivity Curr Opin Psychiatry. 2007 May;20(3):255-61. PMID 17415079
- Smith CF. Association of dietary restraint and disinhibition with eating behavior, body mass, and hunger. Eat Weight Disord. 1998 Mar;3(1):7–15.PMID 11234257
- Bryant EJ, King NA, Blundell JE. Disinhibition: its effects on appetite and weight regulation. Obes Rev. 2008 Sep; 9(5):409-19. Epub 2007 Dec 26. PMID 18179615
- Personality and substance dependence symptoms: modeling substance-specific traits. Grekin ER, Sher KJ, Wood PK. Psychol Addict Behav. 2006 Dec; 20(4):415-24.PMID 17176176
- Young SE et al. Genetic and environmental influences on behavioral disinhibition Am J Med Genet. 2000 Oct 9; 96(5):684-95.PMID 11054778
- Young SE et al. Behavioral disinhibition: liability for externalizing spectrum disorders and its genetic and environmental relation to response inhibition across adolescence. J Abnorm Psychol. 2009 Feb; 118(1):117-30. PMID 19222319
- Emond V, Joyal C, Poissant H. Structural and functional neuroanatomy of attention-deficit hyperactivity disorder (ADHD) Encephale. 2009 Apr;35(2):107-14. Epub 2008 Jul 7. PMID 19393378
- Spiegel DR., Qureshi N., The successful treatment of disinhibition due to a possible case of non-human immunodeficiency virus neurosyphilis: a proposed pathophysiological explanation of the symptoms and treatment. doi:10.1016/j.genhosppsych.2009.01.002
- Aarsland D, Litvan I, Larsen JP Neuropsychiatric symptoms of patients with progressive supranuclear palsy and Parkinson's disease. J Neuropsychiatry Clin Neurosci. 2001 Winter; 13(1):42-9.PMID 11207328
- Eysenck, H.J, Eysenck, S.B.G (1977). Psychoticism as a Dimension of Personality. London: Hodder and Stoughton. ISBN 0-340-20919-4.
- Lester, David (1989). "A NEUROTRANSMITTER BASIS FOR EYSENCK'S THEORY OF PERSONALITY". Psychological Reports 64 (1): 189–190. doi:10.2466/pr0.19184.108.40.206. ISSN 0033-2941. PMID 2564688.
- Zubieta JK. Obsessionality in eating-disorder patients: relationship to clinical presentation and two-year outcome. J Psychiatr Res. 1995 Jul–Aug; 29(4):333-42.PMID 8847659
- Salkovskis PM, Forrester E, Richards C. Cognitive-behavioural approach to understanding obsessional thinking. Br J Psychiatry Suppl. 1998;(35):53–63. PMID 9829027
- Corcoran KM, Woody SR. Appraisals of obsessional thoughts in normal samples. Behav Res Ther. 2008 Jan; 46(1):71–83. PMID 18093572