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.
- Bar-Eli, M. (1997). Psychological performance crisis in competition, 1984–1996: A review. European Yearbook of Sport Psychology, 1, 73–112.
- Eysenck, H. J., & Eysenck, M. W. (1985). Personality and individual differences. New York: Plenum Press.
- 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.
- 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.
- 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.