Motivation and emotion/Book/2014/Extraversion and emotion

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Extraversion and emotion:
How does extraversion influence emotion

Overview[edit]

The humors (11th c., Burgos de Osma)[explain?]

Do extraverts really have more fun? Is life an easier gig for the confident, stress-free and enthusiastic personalities that walk – with great vigour – amongst us? It would seem so. Not only are the extraverted genetically programmed to be happy, they approach life with more risk, constantly search for excitement and engagement, and are inclined to recover from disappointment more rapidly than garden-variety introverts and their neurotic trait neighbours. The extravert is the Big Five’s ‘Big’ personality – the one with the saviour faire, the ability to engage and enjoy, and to socialise with success.

Extraverts tend to exhibit restlessness and impulsivity and are more likely to participate in sport and robust physical activity (Houlihan, 2011). They take more exciting and exotic holidays and figure strongly among sensation seeking tourists – those looking for destinations that offer novelty and risk and leisure activities in exciting outdoor locations (Li & Tsai, 2013). Extraverts are more likely to travel internationally and engage in this travel more often than those categorised as introverted or neurotic (Li & Tsai, 2013). House-bound introverts have been known to fake an extraverted personality in order to be viewed more favourably when interacting in cyberspace (Amichai-Hamburger, Wainapel & Fox, 2002).

Extraverts cope better with life’s many stressors, take difficult challenges in their stride, have a better sense of their abilities, and are more willing to test their problem-solving skills when an issue arises than are other personality types (Connor-Smith & Flaschbart, 2007). They demonstrate more resilience than and show superior levels of persistence in the face of difficulty[factual?].

So, what is it that makes these positive individuals the confident creatures that they are? Much of it is based in genetics and the functions of the brain, but it presents almost as an observable life-force as they go about their lives with a sense of optimism, enthusiasm and general satisfaction. Life as an extrovert is undeniably good[factual?], [grammar?]let’s investigate the many ways in which this manifests itself.

What is an extravert?[edit]

[[Figure 1: File:The humors (11th c.,) Burgos de Osma).jpg| File: Figure1: The humors (11th c.[explain?]]

Extraverted people [[1]] are variously described as outgoing, friendly, gregarious, confident, ‘the life of the party’, fun, and engaged. They are concerned with issues and phenomena beyond the self and interested in their physical and social environments. Extraverts tend to display happy dispositions whether alone or in social situations (Lischetzke, 2006). This happiness correlates with displays of optimism, warmth, emotional stability, sociability and life satisfaction (Costa and McRae, 1980). Extraverts are depicted in psychology and elsewhere as the opposite ‘personality type’ to introverts and own a whole category in the Big Five personality traits.

Carl Jung [[[Wikipedia:Carl Jung|Carl Jung]]] coined the phrase ‘extraversion’ in the 1920s but he was not the first to make an attempt to categorise general personality types or traits. The ancient Greek physician Galen (Jung, 1928) distinguished four temperaments of the sanguine, the phlegmatic, the choleric and the melancholic. Before him, Hippocrates had identified four human elements of air, water, fire and earth, which corresponded to the four bodily substances of blood, phlegm, yellow and black bile (Jung, 1928). While none of these directly correspond to our modern interpretations of personality types, they represent important first steps in differentiating between the manifestations of emotional affect.

Jung saw the extravert/introvert divide as an innate characteristic beginning in childhood, where the extraverted infant was quick to adapt to its environment and less cautious than introverted infants when regarding or approaching objects in that environment (Jung, Routledge). Extraverted individuals grew up to display their psychic perceptions outside themselves when interacting with objects and environment, whereas introverts behaved as if operating internally and feeling the need to defend themselves against external influences.

German-born psychologist Hans Eysenck was the first to develop a scientific two-factor personality trait model that featured Extraversion-Introversion and Neuroticism, to which he later added the category of Psychoticism [[2]]. He hypothesized that extraversion had its roots in cortical arousal (Eysenck, 1967) and extraverts actually required more stimulation than introverts to peak their interest. This can be demonstrated in the extravert’s propensity for sociability and the desire to engage in more exciting or sensational activities. Eysenck was the first among modern psychologists to point to a neurological basis for personality traits, although he only proposed the three different categories.

Costa and McRae (1980) describe an almost systematic happiness in extraverts that influences their subjective well-being. They cite case studies of extraverted paraplegics whose predictions of the future remain as optimistic and buoyant as those of lottery winners. An enduring sense of well-being ensures their objective circumstance does not alter a positive view of their personal outcomes - the hand of fate does not diminish the positive affect. Similarly, an environment of wealth or social privilege has little effect when used as a measure of life satisfaction (Costa & McRae, 1980). There seems to be little doubt that personality traits have a significant influence on emotional affect, and that traits of extraversion are good predictors of positivity and happiness[factual?].

So, an extravert is a generally happy, friendly, outgoing, adaptive, approach oriented, sensation-seeking individual with an enduring sense of well-being and an ability to extract significant satisfaction from everyday life. So far, so good.

Neural/genetic basis of extraversion[edit]

Following on from Eysenck’s contention that personality traits had a neural basis, researchers have made many attempts to gauge the cause or core of extraversion’s positive affect. And it appears that extraverts just can’t help but be happy. Studies show that the ventral striatum, a region of the brain’s ventral tegmental area, is responsible for a positive state affect and a tendency for engagement with the wider world (Hermes, Hagemann, Naumann, & Walter, 2011). The ventral striatal system is also related to approach and appetitive behaviours (Hermes et al., 2011) which are driven by the prospect of reward - and extraverts will most often find these rewards in social situations.

Figure 2: The brain's ventral tegmental area plays a role in extraversive traits

Further experiments have found that extraverts demonstrated a different endocrine response after treatment with a dopamine antagonist, and differences in a gene responsible for coding dopamine receptors. They also demonstrated different[Provide more detail] levels of activity in the ventral striatum during periods of rest or neutral stimulation (Hermes et al., 2011)[explain?].

All of which point to a natural tendency to positive affect and goal-directed approach behavior - a tendency that Jeffrey Gray dubbed in 1970 as the BAS, or Behavioural Activation System (Steel, Schmidt, & Shultz, 2008)[grammar?]. The BAS is influenced by a combination of neural structures including the pre-frontal cortex, hippocampus and the anterior cingulated cortex (Steel et al., 2008) – a powerful cortical coalition aimed at the pursuit of happiness, stimulation and personal well-being. (The BIS, or Behavioural Inhibition System, is usually associated with those characterized by introversion or neuroticism. The link between extraversion and neural circuitry is further supported by research that suggests a strong connection between a genetic predisposition to happiness and the dopamine D4 receptor gene (Tamir, 2009)[explain?][Provide more detail].

Individuals oriented towards extraversion have also been found to possess a link between the pre-frontal areas of the brain associated with amygdala inhibition (Tamir, 2009), which result in higher levels of motivation or arousal when it comes to seeking out happiness-inducing activities. Introverts, on the other hand, seem to prefer a neutral emotional state where they can better assess and avoid perceived external threats. Tamir (2009) contends that extraverts have a greater natural preference for not only experiencing happiness, but also for seeking out happiness-inducing situations through their strong approach behaviour. In other words, extraverts will work for happiness.

BIS/BAS - what motivates an extravert?[edit]

The biopsychological motivation systems first proposed by Gray, (Carver & White, 1994), the Behavioural Inhibition System (BIS) and the Behavioural Activation System (BAS), generally referred to the dimensions of anxiety and impulsivity when studying aspects of personality. Subsequent studies expanded these categories to canvass the areas of reward and punishment, incentive and threat. Carver and White developed the BIS/BAS questionnaire featured later in this section in order to add some robustness to this theory and test it on human subjects, where Gary had mainly worked with animals.

BIS/BAS are stimulus-sensitivity systems that are thought to contribute to specific affective states (Larsen & Ketelaar, 1991) – positive and negative affect – and control an individual’s susceptibility to these states.

Individuals high on the BAS scales have been shown to have higher levels of positive effect, greater propensity to pursue reward and incentive, are more likely to engage in goal and achievement-directed pursuits, and generally perform better in a reward-focused learning environment (Carver & White, 1994). The BAS also provides a fairly constant source of motivation and energy with which to pursue goals and rewards. This sensitivity to reward is demonstrated in high levels of approach behaviour and tangible signs of joy and satisfaction when the goal or reward is achieved. BAS-leaning people, or extraverts, are happy, enthusiastic and confident people.

Interestingly, very high levels of sensitivity to BAS could result in sociopathic tendencies and may even underlie the extreme phases of bipolar disorder (Carver & White, 1994). The lack of inhibition and tendency to impulsivity at the core of the approach behaviour associated with those high on the BAS scales, [grammar?] may also have implications for the development of conduct disorder in children. At the opposite end of behavioural sensitivities, individuals high on the BIS scales may be susceptible to depressive and anxiety disorders and the development of ADHD [[3]] (Carver & White, 1994).

When Carver and White (1994) set out to strengthen Gray’s theory with a factorial questionnaire, they were seeking responses to BAS items that reflected a pursuit of goals, sensitivity to reward, an appetite for new or novel activities, and a tendency to proceed with haste in goal-directed activity. Accordingly, they developed three BAS scales in their inventory based on reward responsiveness, drive and fun-seeking behaviour. Widely used now in many domains of psychology, the BIS/BAS scales are applied in areas as diverse as determining the severity of mental illness, criminal profiling, job suitability and recruitment, and research into anxiety, avoidance and attachment theories and treatments.

How do you fare on the BIS/BAS questionnaire?

Choose from the following four response options:

1: = very true for me; 2: = somewhat true for me; 3: = somewhat false for me; 4: = very false for me

1: A person’s family is the most important thing in life

2: I go out of my way to get the things I want

3: How I dress is important to me

4: Criticism or scolding hurts me quite a bit

5: I’m always willing to try something new if I think it will be fun

6: It’s hard for me to find the time to do things such as get a haircut

7: I worry about making mistakes

8: When I get something I want I feel excited and energised

10: I often wonder why people act the way they do

11: I crave excitement and new sensations

12: It would excite me to win a contest

13: If I think something unpleasant is going to happen I usually get pretty worked up


Table 1: Source: Adapted from Carver, C. S. & White, T. L. (2013). Behavioural activation/inhibition scales. Measurement Instrument Database for the Social Sciences.

Life as an extravert[edit]

Throughout this chapter we have referenced the concept of ‘positive affect’ and the way it determines the day-to-day outlook of the extravert. It is worth devoting some space to investigating this idea of eternal joy! Of course, it’s not every day, in every way, but it is a global way of regarding one’s environment as a fairly juicy apple.

Affect refers to the experience or expression of emotion and is divided into the categories of valence, arousal and motivational intensity. Valence refers to the consequences of emotion, arousal to the activation of the sympathetic nervous system, and motivational intensity to the urge to act. Positive affect is characterised by energy, activity, enthusiasm and alertness and is the emotional state most associated with the traits of extraversion. Many theories exist as to affect’s presence pre- or post-cognition, but many of its effects are subjectively measurable, including gestures and facial expression. Fredrickson (2001) describes affect as consciously accessible feelings that influence physical sensation, attitude and mood.

Testing for positive affect can reliably predict an individual’s attitude or outlook for many years into the future (Costa & McRae, 1980) and is a state that is felt frequently in every day life and in response to most, if not all, situations. It facilitates approach behaviour, and so encourages activity engagement, as has been mentioned in this chapter a number of times previously. Fredrickson (2001) describes a ‘positivity offset’ where individuals experience a mild affect relatively constantly that causes them to engage with their environment and explore novel objects and situations. Without this offset even those with a healthy positive effect would remain unmotivated to action.

As well as being possible to subjectively decipher positive and negative affect, these states are often scientifically measured by the Positive and Negative Affect Schedule, or PANAS. Developed by Clark and Watson in 1988 (Crawford and Henry, 2004), it is a 20 item test with a five-point response scale generally ranging from ‘not at all’ (1), to ‘extremely’ (5). It is designed to show relations between positive and negative affect and personality factors and traits. Clark and Watson claimed responses to PANAS could demonstrate the independence of positive and negative affect, but this is an area of debate between personality psychologists (Crawford & Henry, 2004). Many argue that the affects – positivity and negativity – being measured with PANAS are merely opposite poles of the same dimension (Crawford & Henry, 2004). In an attempt to determine the causality of affect, McNiel & Fleeson (2006) were even able to manipulate levels of state extraversion and state neuroticism within experiment participants.

Although the argument that positive and negative affect are just extremes of the one dimension does exist, PANAS is generally regarded as a reliable and valid measure of affect and one that has been shown to decipher between the constructs of anxiety and depression – an historically difficult differentiation to make in clinical situations (Crawford & Henry, 2006). It also exists in shortened and elongated versions and a children’s version has been adapted, demonstrating its utility as a psychometric instrument.

The following table shows two historically different scientific approaches to the measurement of positive and negative affect and what it takes (mathematically) to 'make' an extravert[explain?].

Eysenck's Model
PA = (+)E + (0)N NA = (0)E + (+)N
Gray/Newman Model
PA = (+)E + (+)N + (+)(ExN) NA = (-)E + (+)N + (-)(ExN)

Table 2: Regression equations of theoretical models comparing the positive (PA) and negative (NA) affects of Extraversion (E) and Neuroticism (N). (Source: Rusting & Larsen, 1997)

Coping style[edit]

The desirable effects of positive affect can also influence reactions to stress and trauma in extraverts. These events have the ability to confront individuals about their world view and assumptions of themselves and others (Zakowski, Herzer, Barrett, Milligan & Beckman, 2010). An extravert’s ability to be more emotionally expressive in times of stress or trauma opens up a far greater array of coping strategies than their neurotic cohorts[factual?]. They[who?] will tend to seek support or look for release in the written disclosure of their problems or fears far more readily that those with traits of neuroticism. In a US study of cancer patients, Zakowski et al. (2010) found that while extraversion seemed to have no mediating effect on patients who participated in a written expression exercise, high neurotic participants suffered significant negative effects from the disclosure process.

Likewise, those high in positive affect are also likely to have high levels of self-efficacy (Ebstrup, Eplov, Pisinger & Jorgensen, 2011) – where individuals judge their ability and belief in themselves to carry out novel or challenging tasks or stare down a difficult situation. Those high in self-efficacy will choose more challenging tasks, create higher benchmarks, and are generally more persistent and resilient than those low with negative affect of low self-efficacy (Ebstrup et al., 2011). Many studies also show that those high in self-efficacy tend to perceive stressful situations as a challenge to rise to rather than a stress factor (Ebstrup et al., 2011). Those high in positive affect and extraversion have also been found to be more accomplished at problem solving and cognitive restructuring than personalities from other categories (Connor-Smith & Flachsbart, 2007).

In meta-analysis, extraversion emerges as an accurate predictor of positive affect and life satisfaction and rates highly in facet scores of warmth, gregariousness, assertiveness and excitement- seeking (Steel, Schmidt & Shultz, 2008). Extraversion also has a very strong relationship with subjective well-being (Steel, Schmidt Schultz, 2008) which may explain the curiosities of the ‘happiness paradox’, where personal evaluations of well-being remain stable or even decrease as the wealth of a country or economy increases – another victory for nature over nurture!

Figure 3: It seems extraverts just can't stop that positive vibe!

A robust approach to living[edit]

In their approach to life’s happier or more leisurely pursuits – sport, travel, web-surfing, friendship groups – extraverts continue to demonstrate a healthy, robust attitude to engaging with life. When compared to individuals from other Big Five personality types, extraverted athletes showed higher levels of effort and generally more effective coping strategies when dealing with a self-selected stressor in a sport ( Kaiseler, Polman & Nicholls et al., 2012). Extraverts were inclined to use higher levels of problem-solving strategies and to seek informational social support when dealing with their athletic stressor. In Kaiseler et al’s (2012) research, extraverted athletes were also more likely to seek emotional support than participants high in neuroticism, who viewed the experimental stressor more as a threat to be avoided rather than an obstacle to be overcome.

Only in the area of active coping on the field were extraverts shown to revert to a passive state in Kaiseler et al’s (2012) study[explain?]. Referees and their decisions are, it seems, one of the few domains to possess immunity against the charms and social skills of the extravert athlete!

Even in the area of Lateralised Readiness Potential (LRP) [[[Wikipedia:Lateralized Readiness Potential|Lateralized Readiness Potential]]], an indicator of the central activation of motor responses, extraverts have the upper hand. Already[say what?], compared to introverts, extraverts are more physically active, have a higher involvement in contact sport, and tend to be more restless in restrictive physical environments (Houlihan & Stelmack, 2011).

In tests of motor activity they demonstrate more frequent movements and faster reaction times than introverts. Even in cognitive tasks, extravert’s reaction and movement times were faster than others. In LRP, they demonstrated faster initiation of movement than introvert participants, although their no-go errors (false alarms) were shown in one experiment to be slightly higher (Houlihan & Stelmack, 2011) – probably all that impulsivity they are noted for!

They may well be faster to a button, but extroverts have also shown a higher level of acting upon intentions to exercise, although only at a moderate rate. De Bruijn et al. (2009) found that, although the intention was high, the actual enactment of exercise wasn’t always present. This could be explained, De Bruijn et al. say, by the extravert’s general high level of daily activity which lends itself to a constant, drip-fed, level of movement and engagement, rather than the vigorous, but shorter-burst, activity levels of their Conscientious cohorts.

Extraverts also take a robust approach to travel, [grammar?] where they have been found to seek excitement and sensation, preferably with exotic outdoor leisure pursuits, in their destinations (Li & Tsai, 2013). They are also much more likely to travel internationally than introverted characters as they seek novelty, risk and daring that they can’t find domestically (Li & Tsai, 2013). Personalities with low levels of sensation-seeking will tend to holiday in familiar locations and are much less likely to travel internationally. Extraversion and sensation-seeking have significant implications for the international travel industry (Li & Tsai, 2013), where tourism providers seek to tailor adventure and novelty-based packages for this market sector. Li and Tsai (2013) even found that those who actually had international travel experience were far more likely to be extraverts than introverts - impulsivity and the restless search for challenge find another outlet!

When making friends and exercising social skills, even in the midst of the present day social media mania, extraverts tend to find and form their friendships and relationships through traditional face-to-face social interaction (Amichai-Hamburger, Wainapel & Fox, 2002). Unlike their introverted cohorts who find that social media offers them anonymity and freedom from social expectation, extraverts find their ‘real me’ and ‘real friends’ in real-life social situations (Amichai-Hamburger, et al. 2002). Even though extraverts will still use social media to chat to and possibly meet others, their preferred social interactions do not occur in cyberspace.

And while they are busy forming these face-to-face friendships, extraverts tend to also develop large social networks in comparison with other personality types (Pollett, Roberts & Dunbar, 2011). As extraverts tend to have superior social skills, enjoy social activities and also enjoy the attention they attract while taking part in these activities, their networks naturally tend to be large and cross-sectional. Whether these networks are of a higher quality than other people have is subject to conjecture (Pollett et al., 2011), but extraverts have been shown to enjoy greater support from members of their friendship networks and turn to them more often for information and advice. Pollett et al. (2011) found that extraverts had larger and more supportive networks at every layer of friendship – the innermost support group, the next layer called the sympathy group, and the outer layer which consists of members who are less emotionally close and contacted far less often than the other group members.

Conclusion[edit]

Yep, it’s official – extraverts are in personality heaven! Life is attacked with more enthusiasm, returns greater yields, and, while you may face the same problems along the way as others, when you’re an extravert, it doesn’t seem to matter as much. You have more friends and social support, greater life satisfaction, get more out of your leisure time, view challenges with relish, and bounce back quicker from negative circumstances.

Extraverts have more acute motor skills, participate more vigorously in sport and physical activity, and will work harder to have a better time at a party (or anything else). Apart from the risks that being impulsive may pose from time to time, and the remote possibility you may develop sociopathic tendencies, the influence on your emotions from the positive affect that is the hallmark of the extravert, is nearly 100% good.

See also[edit]

References[edit]

Amichai-Hamburger, Y., Wainapel, G., & Fox, S. (2002). “On the internet no one knows I’m an introvert”: Extroversion, neuroticism and internet interaction. Cyber Psychology and Behaviour, 5(2), 125-128.

Carver, C. S. & White, T. L. (2013). Behavioural Activation/Inhibition (BIS/BAS) scales. Measurement Instrument Database for the Social Sciences. Retrieved from www.midss.ie 20 October 2014

Carver, C. S. & White, T. L. (1994). Behavioural inhibition, behavioural activation, and affective responses to impending reward and punishment: The BIS/BAS scales. Journal of Personality and Social Psychology, 67(2), 319-333.

Connor-Smith, J. K. & Flachsbart, C. (2007). Relations between personality and coping: A meta-analysis. Journal of Personality and Social Psychology, 93(6), 1080-1107. doi: 10.1037//0022-3514.93.6.1080

Costa, P. T., & McRae, R. R. (1980). Influence of extraversion and neuroticism on subjective well-being: Happy and unhappy people. Journal of Personality and Social Psychology, 38(4), 668-678.

Crawford, J. R. & Henry, J. D. (2004). The positive and negative affect schedule (PANAS): Construct validity, measurement properties and normative data in a large non-clinical sample. British Journal of Clinical Psychology 43, 245-265.

De Bruijn, G-J., de Groot, R., van den Putte, B. & Rhodes, R. (2009). Conscientiousness, extroversion and action control: Comparing moderate and vigorous physical activity. Journal of Sport and Exercise Psychology, 31, 724-742.

Eaves, L. & Eysenck, H. J. (1975). The nature of extraversion: A genetic analysis. Journal of Personality and Social Psychology, 32(1), 101-112.

Ebstrup, J. E., Eplov, L. F., Pisinger, C. & Jorgensen, T. (2011). Association between five factor personality traits and perceived stress: Is the effect mediated by general self-efficacy? Anxiety, Stress and Coping, 4, 407-419. doi: 10.1080/10615806.2010.540012

Eysenck, H. J. (1967). The biological basis of personality. Springfield, IL: Thomas Publishing

Fredrickson, B. L. (2001). The role of positive emotions in positive psychology. The broaden and build theory of positive emotions. American Psychologist, 56(3), 218-226. doi: 10.1037//0003-066X.56.3.218

Hermes, M., Hagemann, D., Naumann, E. & Walter, C. (2011). Extraversion and its positive core – further evidence from neuroscience. Emotion, 11(2), 367-378. doi: 10.1037/a0021550

Houlihan, M., & Stelmack, R. M. (2011). Extraversion and Motor Response Initiation: Further analysis of the lateralized readiness potential. Journal of Individual Difference, 32(2), 103-109. doi: 10.1027/1614-0001/a000041

Jung, C. G. (1928). Psychological types. In Routledge & Keegan, P. (Eds.), Contributions to Analytical Psychology (pp 295-312). London, Angus & Robertson.

Kaiseler, M., Polman, R. C. J. & Nicholls, A. R. (2012). Effects of the Big Five personality dimensions on appraisal coping, and coping effectiveness in sport. European Journal of Sport Science, 12(1), 62-72. doi: .org/10.1080/17461391.2010.551410

Larsen, R. J. & Ketelaar, T. (1991). Personality and susceptibility to positive and negative emotional states. Journal of Personality and Social Psychology, 61(1), 132-140.

Li, C-Y. & Tsai, B-K. (2013). Impact of extraversion and sensation seeking on international tourism choices. Social Behaviour and Personality, 41(2), 327-334. doi: 10.2224/sbp.2013.41.2.327

Lischetzke, T. & Eid, M. (2006). Why extraverts are happier than introverts: The role of mood regulation. Journal of Personality, 74(4), 1127-1162. doi: 10.1111/j.1467-6494.2006.00405.x

McNiel, J. M. & Fleeson. W. (2006). The causal effects of extraversion on positive affect and neuroticism on negative affect: manipulating state extraversion and state neuroticism in an experimental approach. Journal of Research in Personality, 40, 529-550. doi: 10.1016/j.jrp.2005.05.003

Pollett, T. V., Roberts, S. G. B., & Dunbar, R. I. M. (2011). Extraverts have larger social network layers, but so not feel emotionally closer to individuals at any layer. Journal of individual Differences,32(3), 161-169. doi: 10.1027/1614-0001/a000048

Rosellini, A. J., Lawrence, A. E., Meyer, J. F. & Brown, T. A. (2010). The effects of temperament on agoraphobia in panic disorder. Journal of Abnormal Psychology, 119(2), 420-426. doi: 10.1037/a0018614

Rusting, C. L., & Larsen, R. J. (1997). Extraversion, neuroticism and susceptibility to positive and negative affect: A test of two theoretical models. Personality and Individual Differences, 22(5), 607-612.

Steel, P., Schmidt, J., & Shultz, J. (2008). Refining the relationship between personality and subjective well-being. Psychological Bulletin, 134(1), 138-161. doi: 10.1037/0033-2909.134.1.138

Tamir, M. (2009). Differential preferences for happiness: Extraversion and trait-consistent emotion regulation. Journal of Personality, 77(2), 447-470. doi: 10.1111/j.1467-6494.2008.00554.x

Zakowski, S. G., Herzer, M., Barrett, S. D., Milligan, J.G. & Beckman, N. (2011). Who benefits from emotional expression? An examination of personality differences among gynaecological cancer patients participating in a randomized controlled emotional disclosure intervention trial. British Journal of Psychology, 102, 355-372. doi: 10.1348/0007I26I0X524949