Neuroticism

Neuroticism is a fundamental personality trait in the study of psychology. It is an enduring tendency to experience negative emotional states. Individuals who score high on neuroticism are more likely than the average to experience such feelings as anxiety, anger, guilt, and depressed mood.^[1] They respond more poorly to environmental stress, and are more likely to interpret ordinary situations as threatening, and minor frustrations as hopelessly difficult. They are often self-conscious and shy, and they may have trouble controlling urges and delaying gratification. Neuroticism is associated with low emotional intelligence, which involves emotional regulation, motivation, and interpersonal skills.^[2] It is also a risk factor for "internalizing" mental disorders such as phobia, depression, panic disorder, and other anxiety disorders (traditionally called neuroses).^[3][4][5]

Emotional stability

On the opposite end of the spectrum, individuals who score low in neuroticism are more emotionally stable and less reactive to stress. They tend to be calm, even-tempered, and less likely to feel tense or rattled. Although they are low in negative emotion, they are not necessarily high on positive emotion. Being high on positive emotion is an element of the independent trait of extraversion. Neurotic extraverts, for example, would experience high levels of both positive and negative emotional states, a kind of "emotional roller coaster". Individuals who score low on neuroticism (particularly those who are also high on extraversion) generally report more happiness and satisfaction with their lives.^[6]

Measurement

Like other personality traits, neuroticism is typically viewed as a continuous dimension, rather than as a distinct type of person. People vary in their level of neuroticism, with a small minority of individuals scoring extremely high or extremely low on the dimension. Because most people cluster around the average, neuroticism test scores approximate a normal distribution, given a large enough sample of people. Neuroticism is one of the most studied personality traits in psychology, and this has resulted in a wealth of data and statistical analysis. It is measured on the EPQ, the NEO PI-R, and other personality inventories.

Neuroticism has also been studied from the perspective of Gray's biopsychological theory of personality, using a scale that measures personality along two dimensions: the Behavioural Inhibition System (BIS) and the Behavioural Activation System (BAS).^[7][8] The BIS is thought to be related to sensitivity to punishment as well as avoidance motivation, while the BAS is thought to be related to sensitivity to reward as well as approach motivation. Neuroticism has been found to be positively correlated with the BIS scale, and negatively correlated with the BAS scale.^[9][10]

Physiology

Neuroticism appears to be related to physiological differences in the brain. Hans Eysenck theorized that neuroticism is a function of activity in the limbic system, and his research suggests that people who score highly on measures of neuroticism have a more reactive sympathetic nervous system, and are more sensitive to environmental stimulation.^[11] Behavioral genetics researchers have found that a significant portion of the variability on measures of neuroticism can be attributed to genetic factors.^[12]

A study with positron emission tomography has found that healthy subjects that score high on the NEO PI-R neuroticism dimension tend to have high altanserin binding in the frontolimbic region of the brain — an indication that these subjects tend to have more of the 5-HT_2A receptor in that location.^[13] Another study has found that healthy subjects with a high neuroticism score tend to have higher DASB binding in the thalamus; DASB is a ligand that binds to the serotonin transporter protein.^[14]

Another neuroimaging study using magnetic resonance imaging to measure brain volume found that the brain volume was negatively correlated to NEO PI-R neuroticism when correcting for possible effects of intracranial volume, sex, and age.^[15]

Other studies have associated neuroticism with genetic variations, e.g., with 5-HTTLPR — a polymorphism in the serotonin transporter gene.^[16] However, not all studies find such an association.^[17] A genome-wide association study (GWA study) has associated single-nucleotide polymorphisms in the MDGA2 gene with neuroticism,^[18] however the effect sizes were small. Another GWA study gave some evidence that the rs362584 polymorphism in the SNAP25 gene was associated with neuroticism.^[19]

A 2009 study has found that higher neuroticism is associated with higher decreased brain size with increasing age.^[20]

Mental-noise hypothesis

Studies have found that the mean reaction times will not differ between individuals high in neuroticism and those low in neuroticism, but that there is considerably more trial-to-trial variability in performance reflected in reaction time standard deviations. In other words, on some trials neurotic individuals are faster than average, and on others they are slower than average. It has been suggested that this variability reflects noise in the individual's information processing systems or instability of basic cognitive operations (such as regulation processes), and further that this noise originates from two sources: mental preoccupations and reactivity processes.^[21]

Flehmig et al. (2007) studied mental noise in terms of everyday behaviours using the Cognitive Failures Questionnaire which is a self-report measure of the frequency of slips and lapses of attention. A slip is an error by commission, and a lapse is an error by omission. This scale was correlated with two well-known measures of neuroticism (the BIS/BAS scale and the Eysenck Personality Questionnaire). Results indicated that the CFQ-UA subscale was most strongly correlated with neuroticism (r = .40) and explained the most variance (16%) compared to overall CFQ scores which only explained 7%. The authors interpret these findings as suggesting that mental noise is "highly specific in nature" as it is related most strongly to attention slips triggered endogenously by associative memory. In other words, this may suggest that mental noise is mostly task-irrelevant cognitions such as worries and preoccupations.^[22]

Geography

Neuroticism, along with other personality traits, has been mapped across states in the USA. People in eastern states such as New York, New Jersey, West Virginia, and Mississippi tend to score high on neuroticism, whereas people in many western states, such as Utah, Colorado, South Dakota, Oregon, and Arizona score lower on average. People in states that are higher in neuroticism also tend to have higher rates of heart disease and lower life expectancy.^[23]

Evolutionary psychology

One of the theories regarding evolutionary approaches to depression‎ focuses on neuroticism. A moderate amount of neuroticism likely have certain beneficial effects such as increased drive and productivity due to greater sensitivity to negative outcomes and may increase a person's inclusive fitness but too much may reduce this by for example recurring depressions. Thus, evolution will select for an optimal amount and most people will have neuroticism near this optimum. However, since neuroticism likely has a normal distribution in the population, a minority will have very high (and low) neuroticism.^[24]

Core self-evaluations

Main article: Core self-evaluations

Neuroticism has been included as one of the four dimensions that comprise core self-evaluations, one's fundamental appraisal of oneself, along with locus of control, self-efficacy, and self-esteem. ^[25] The concept of core self-evaluations was first examined by Judge, Locke, and Durham (1997), ^[25] and since has proven to have the ability to predict several work outcomes, specifically, job satisfaction and job performance.^{[26][27][25][28][29]}

See also

• Big Five personality traits
• Personality
• Trait theory
• Psychoticism
• Highly sensitive person

References

1. ^ G. Matthews and Ian J. Deary (1998). Personality traits. Cambridge, UK: Cambridge University Press. 
2. ^ Daniel Goleman (1997). Emotional Intelligence. New York: Bantam. 
3. ^ Hettema, J. M., Neale, M. C., Myers, J. M., Prescott, C. A., & Kendler, K. S. (2006). A population-based twin study of the relationship between neuroticism and internalizing disorders. American journal of Psychiatry, 163, 857–864.
4. ^ http://www.springerlink.com/content/h011745713t7l243/
5. ^ http://books.google.co.uk/books?id=1gJPXv5wQbIC&pg=PA288&lpg=PA288&dq=introversion+masturbation&source=bl&ots=rlMwXBEAvh&sig=zcqFeLIwTArP-ugnsfiZDMum2zg&hl=en&ei=n-TWS7n-I8_6_Abrqpm3Bw&sa=X&oi=book_result&ct=result&resnum=7&ved=0CBUQ6AEwBjgK#v=onepage&q&f=false
6. ^ Michael W. Passer; Ronald E. Smith (2009). Psychology: the science of mind and behaviour. McGraw-Hill Higher Education. ISBN 9780077118365. http://books.google.com/books?id=9eFaAAAACAAJ. 
7. ^ Gray, J.A. (1981). A critique of Eysenck's theory of personality, In H.J. Eysenck (Ed.) A model for personality (pp 246–276)
8. ^ Gray, J.A. (1982). The neuropsychology of anxiety: An enquiry into the functions of the septo-hippocampal system.
9. ^ Boksema, M.A.S, Topsa, M., Westera, A.E., Meijmana, T.F. & Lorist, M.M. (June 2006). "Error-related ERP components and individual differences in punishment and reward sensitivity". Brain Research 1101 (1): 92–101. doi:10.1016/j.brainres.2006.05.004. PMID 16784728. 
10. ^ Carver, C.S. & White, T.L. (1994). "Behavioral Inhibition, Behavioral Activation, and Affective Responses to Impending Reward and Punishment: The BIS/BAS Scales". Journal of Personality and Social Psychology 67 (2): 319–333. doi:10.1037/0022-3514.67.2.319. 
11. ^ Hans Jürgen Eysenck and Michael W. Eysenck (1985). Personality and individual differences: A natural science approach. Perspectives on individual differences. Plenum Press (Springer). ISBN 0306418444. 
12. ^ Viken RJ, Rose RJ, Kaprio J, Koskenvuo M. (April 1994). "A developmental genetic analysis of adult personality: extraversion and neuroticism from 18 to 59 years of age.". Journal of personality and social psychology 66 (4): 722–30. doi:10.1037/0022-3514.66.4.722. PMID 8189349. 
13. ^ Vibe G. Frøkjær, Erik L. Mortensen, Finn Årup Nielsen, Steven Haugbøl, Lars H. Pinborg, Karen H. Adams, Claus Svarer, Steen G. Hasselbalch, Søren Holm, Olaf B. Paulson and Gitte Moos Knudsen (2007). "Frontolimbic Serotonin 2A Receptor Binding in Healthy Subjects Is Associated with Personality Risk Factors for Affective Disorder". Biological Psychiatry 66 (6): 722. doi:10.1016/j.biopsych.2007.07.009. PMID 17884017. 
14. ^ Akihiro Takano, Ryosuke Arakawaa, Mika Hayashia, Hidehiko Takahashia, Hiroshi Itoa & Tetsuya Suhara (September 2007). "Relationship between neuroticism personality trait and serotonin transporter binding". Biological Psychiatry 62 (6): 588–592. doi:10.1016/j.biopsych.2006.11.007. PMID 17336939. 
15. ^ Brian Knutsona, Reza Momenan, Robert R. Rawlings, Grace W. Fong and Daniel Hommer (November 2001). "Negative association of neuroticism with brain volume ratio in healthy humans". Biological Psychiatry 50 (9): 685–690. doi:10.1016/S0006-3223(01)01220-3. PMID 11704075. 
16. ^ Klaus-Peter Lesch, D. Bengel, A. Heils, S. Z. Sabol, B. D. Greenberg, S. Petri, J. Benjamin, C. R. Muller, D. H. Hamer, & Dennis L. Murphy (November 1996). "Association of anxiety-related traits with a polymorphism in the serotonin transporter gene regulatory region". Science 274 (5292): 1527–1521. doi:10.1126/science.274.5292.1527. PMID 8929413. 
17. ^ A. F. Jorm, A. S. Henderson, P. A. Jacomb, H. Christensen, A. E. Korten, B. Rodgers, X. Tan & S. Easteal (September 1998). "An association study of a functional polymorphism of the serotonin transporter gene with personality and psychiatric symptoms". Molecular Psychiatry 3 (5): 449–441. doi:10.1038/sj.mp.4000424. PMID 9774781. 
18. ^ E. J. van den Oord, P. H. Kuo, A. M. Hartmann, B. T. Webb, H. J. Möller, J. M. Hettema, I. Giegling, J. Bukszár, D. Rujescu (September 2008). "Genomewide Association Analysis Followed by a Replication Study Implicates a Novel Candidate Gene for Neuroticism". Archives of General Psychiatry 65 (9): 1062–1071. doi:10.1001/archpsyc.65.9.1062. PMID 18762592. http://archpsyc.ama-assn.org/cgi/content/abstract/65/9/1062. 
19. ^ A. Terracciano, S Sanna, M. Uda, B. Deiana, G. Usala, F. Busonero, A. Maschio, M. Scally, N. Patriciu, W.-M. Chen, M. A. Distel, E. P. Slagboom, D. I. Boomsma, S. Villafuerte, E. S. liwerska, M. Burmeister, N. Amin, A. C. J. W. Janssens, C. M. van Duijn, D. Schlessinger, G. R. Abecasis and P. T. Costa Jr (October 2008). "Genome-wide association scan for five major dimensions of personality". Molecular Psychiatry 15 (6): 647–56. doi:10.1038/mp.2008.113. PMC 2874623. PMID 18957941. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2874623. 
20. ^ Jackson, J.; Balota, D.; Head, D. (2009). "Exploring the relationship between personality and regional brain volume in healthy aging.". Neurobiol Aging. doi:10.1016/j.neurobiolaging.2009.12.009. ISSN 0197-4580. PMC 2891197. PMID 20036035. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2891197. Lay summary.  edit
21. ^ Robinson, M.D & Tamir, M. (2006). "Neuroticism as mental noise: a relation between neuroticism and reaction time standard deviations.". Journal of Personality and Social Psychology 89 (1): 107–114. doi:10.1037/0022-3514.89.1.107. PMID 16060749. 
22. ^ Flehmig, H.C., Steinborn, M., Langner, R., & Westhoff, K. (2007). "Neuroticism and the mental noise hypothesis: Relationships to lapses of attention and slips of action in everyday life.". Psychology Science 49 (4): 343–360. 
23. ^ Stephanie Simon (2008-09-23). "The United States of Mind. Researchers Identify Regional Personality Traits Across America". WSJ.com. http://online.wsj.com/article/SB122211987961064719.html?mod=yhoofront.  Original research article: Peter J. Rentfrow, Samuel D. Gosling and Jeff Potter (2008). "A Theory of the Emergence, Persistence, and Expression of Geographic Variation in Psychological Characteristics". Perspectives on Psychological Science 3 (5): 339–369. doi:10.1111/j.1745-6924.2008.00084.x. http://www3.interscience.wiley.com/journal/121394239/abstract. 
24. ^ Allen, N.; Badcock, P. (2006). "Darwinian models of depression: A review of evolutionary accounts of mood and mood disorders". Progress in Neuro-Psychopharmacology and Biological Psychiatry 30 (5): 815–826. doi:10.1016/j.pnpbp.2006.01.007. PMID 16647176.  edit
25. ^ ^{a b c} Judge, T. A., Locke, E. A., & Durham, C. C. (1997). The dispositional causes of job satisfaction: A core evaluations approach. Research in Organizational Behavior, 19, 151–188.
26. ^ Bono, J. E., & Judge, T. A. (2003). Core self-evaluations: A review of the trait and its role in job satisfaction and job performance. European Journal of Personality, 17(Suppl1), S5-S18. doi:10.1002/per.48
27. ^ Dormann, C., Fay, D., Zapf, D., & Frese, M. (2006). A state-trait analysis of job satisfaction: On the effect of core self-evaluations. Applied Psychology: An International Review, 55(1), 27-51.
28. ^ Judge, T. A., Locke, E. A., Durham, C. C., & Kluger, A. N. (1998). Dispositional effects on job and life satisfaction: The role of core evaluations. Journal of Applied Psychology, 83(1), 17-34.
29. ^ Judge, T. A., & Bono, J. E. (2001). Relationship of core self-evaluations traits—self-esteem, generalized self-efficacy, locus of control, and emotional stability—with job satisfaction and job performance: A meta-analysis. Journal of Applied Psychology, 86(1), 80-92.