Extraversion and Introversion

Extraversion–introversion  is  a  personality  factor that refers to the degree to which a person’s basic orientation  is  turned  inward  (toward  oneself)  or outward  (toward  the  external  world).  Introverts are said to be shy and prefer to work alone; they tend to withdraw into themselves, especially when they  experience  emotional  stress  and  conflict.  In contrast, extraverts are said to be sociable and prefer occupations that enable them to work directly with other people; when experiencing stress, they will tend to seek company.

Another  related  personality  factor  is  emotional instability–stability  (or  neuroticism),  which  is  a continuum of emotionality that varies from moody, anxious, temperamental, and maladjusted persons in the unstable or neurotic end, as opposed to stable people, who are said to be calm and well adjusted.

These two personality factors are strongly associated with the name of Hans Eysenck. In psychology, the question of which primary source accounts for the apparent variance in human behavior has long  been  debated.  The  proponents  of  the  trait approach  advocated  stable,  intraorganismic  constructs as the main determinants of behavior. One of the most noted of the trait researchers during the 1960s and the 1970s was Eysenck, who conceived traits  as  relative.  This  psychologist  used  psychiatrists’  ratings  of  patients’  characteristics  to  arrive at  two  superordinate  personality  factors  ranging on continuums, namely introversion–extraversion and  emotional  instability–stability  (better  known as neuroticism); these most significant dimensions emerged from many factor-analytic studies of the intercorrelations between numerous and different traits.

Strictly  speaking,  these  two  personality  factors only  provide  phenotypic  descriptions;  therefore, Eysenck  also  suggested  causal  explanations  on the  biological  level.  He  interpreted  the  introversion–extraversion dimension as being based on the balance between cortical excitation and inhibition. Excitation  is  related  to  the  facilitation  of  perceptual, cognitive, and motor responses in the central nervous  system,  whereas  inhibition  is  related  to the  exact  opposite  effect,  namely  the  suppression of  such  responses.  Emotionality  or  neuroticism is  biophysically  explained  through  the  instability of  the  autonomous  neural  system;  it  is  assumed that  an  autonomous  response  is  dependent  on  a  person’s  constitutional  structure,  which  mediates the  strength  of  his  or  her  responses  to  incoming stimuli. Thus, it is the autonomous neural system that is most probably the basis of individual differences concerning emotionality.

Trait  theorists  have  typically  used  objective inventories  that  involved  direct  quantification  of personality dimensions, without intervening interpretations of participants’ responses. Such was the Eysenck  Personality  Inventory  (EPI),  which  was among  the  most  popular  trait  inventories  taken from general psychology and used during the 1960s and 1970s in early sport personality research. The basic idea here was to try and “match” athletes to sport  disciplines;  for  example,  it  was  argued  that an  extravert’s  cortex  is  less  aroused  than  that  of an introvert, and therefore an extravert will need much stronger external stimuli than the introvert, who will in turn suffer from such a strongly stimulating environment; an introvert will clearly prefer a weak environmental stimulation.

According to this line of reasoning, if (a) lower cortical  arousal  is  mostly  related  to  extraversion and higher cortical arousal to introversion, and (b) minor arousal fluctuations are more typical of emotionally stable people and substantial arousal fluctuations are mostly apparent in neurotics, then we could argue that for an elite athlete, although being stable is almost always better than being unstable, the performance quality of introverts versus extraverts will depend on the task (sport discipline) to be performed. Thus, as demonstrated, for example, by J. E. Kane, in a stressful environment when the fulfillment  of  a  complex  task  is  required,  as  in  a basketball game, stable extraverts seem to exhibit motor advantage not only over unstable extraverts, but also over stable introverts (and in particular, of course, over unstable introverts). By contrast, stable introverts will enjoy an advantage in sport disciplines  such  as  marathon  running,  long-distance swimming, or rifle shooting, which are monotonic and environmentally poorly stimulating.

For  the  aforementioned  reasons,  it  was  particularly  the  introversion–extraversion  dimension that  caught  the  attention  of  much  of  the  sport personality research from its earliest days. In general, athletes’ personality structures were found to lean toward extraversion, which is not quite surprising given the larger numbers of people actively engaged in extravert sports (team sports such as football or basketball).  However,  lone  athletes  like  marathon runners were indeed found to be more introverted; moreover, it was found that top, superior athletes tended  to  be  more  introverted  in  comparison  to lower level athletes, even within extravert samples (not  to  mention  introvert  ones).  Kane  contended that superior athletes of all sport disciplines enjoy the  advantage  of  being  able  to  isolate  themselves better  in  order  to  appropriately  concentrate  and prepare  for  task  performance,  an  ability  which  is clearly related to introverted tendencies.

Despite  the  fact  that  Eysenck  has  been  one  of the most cited psychologists of his time, and even though  his  two  previously  mentioned  factors  are included  among  the  Big  Five  of  personality,  it seems  that  simply  knowing  someone’s  personality  trait  will  not  really  help  to  predict  how  that person will perform under specific circumstances. Accordingly,  sport-personality  research  waned toward  the  1980s  and  1990s,  probably  because much  of  this  research  resulted  in  what  were viewed  as  statistically  significant  differences  that were often meaningless. However, questions, such as whether extraverts will perform better in team situations  and  introverts  in  individual  ones,  can lead  to  more  accurate  predictions  of  athletes’ behavior  in  comparison  to  relying  only  on  traits, or alternatively, only on situations.

It  may  therefore  be  possible  to  more  usefully apply Eysenck’s two factors within an interactionist framework, such as the one suggested by Robin Vealey. Strictly speaking, the basic idea mentioned above,  namely  that  of  matching  individuals  and sports,  actually  reflects  an  interactionist  perspective.  Moreover,  transactionist  approaches  such  as Michael  Bar-Eli’s  crisis  theory,  in  which  introversion–extraversion  and  neuroticism  were  included in a reconceptualization of athletes’ prestart states, should be encouraged in order to more fully exploit the potential concealed in these two big personality factors, and further advance our understanding of sport behavior.


  1. Bar-Eli, M. (1997). Psychological performance crisis in competition, 1984–1996: A review. European Yearbook of Sport Psychology, 1, 73–112.
  2. Eysenck, H. J., & Eysenck, M. W. (1985). Personality and individual differences. New York: Plenum Press.
  3. Kane, J. E. (1978). Personality research: The current controversy and implications for sports studies. In W. F. Straub (Ed.), Sport psychology: An analysis of athlete behavior (pp. 228–240). Ithaca, NY: Mouvement.
  4. McCrae, R. R., & Costa, P. T. (1999). A five-factor theory of personality. In L. A. Pervin (Ed.), Handbook of personality theory and research (pp. 139–153). New York: Guilford Press.
  5. Vealey, R. S. (2002). Personality and sport behavior. In T. S. Horn (Ed.), Advances in sport psychology (2nd ed., pp. 43–82). Champaign, IL: Human Kinetics.

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