日本大学歯学部紀要 39，1‑10，2011

Extraversion and introversion in second‑language acquisition :a literature review
Eric Wong
Abstract
This paper is a chronological literature review of how the Individual Learner Differences(ID)of Extraversion‑Introversion (E‑I)were used in second language acquisition.A Japanesecontext was sought when possible.CALP and BICS and its relationship with E‑I are discussed. Teachers take for granted that students who speak more tend to be better at learning
languages.Ifthis is the case then a knowledge ofE‑I will be ofmajor benefit to teachers when
they plan and teach their classes.The literature cites many instances where E‑I does have an
influence on both first and second language learning. However, a standardized working
definition of E‑I is elusive. Another problem associated with the use of E‑I included finding
an appropriate instrument from a long list of measuring devices that is sensitive enough andreliable to measure E‑I. Finally, this paper looks at how these measures can be used inlanguage teaching. The conclusion drawn indicate that while there is strong evidence tosuggest that E‑I plays a role in language acquisition,clearly more work needs to be done infine‑tuning the instruments used to measure E‑I.
Key words: BICS and CALPS, Differences (ID), Extraversion‑Introversion (E‑I),
Individual Learner M easuring

Extraversion‑Introversion and Language Learning
As a teacher with experience at several junior high schools in Japan, I have taught manykinds of students. One of the characteristics I have noticed from my students is that theirpersonality plays a vital role in their studies.From myobservations I have found that extraverted students, by virtue of their outgoingness, easily communicate in English even though theymight not produce accurate output. On the other hand, many introverted students have an
obsession with producing accurate sentences and take the time to compose and produce correct
forms.
I am interested in Extraversion‑Introversion (E‑I) because I believe that E‑I is a gateway
through which teachers can manipulate the learning of their students.Teachers will be able totailor their lessons so that students obtain the maximum benefit from them. Of course, thetailoring of lessons depends on manyvariables such as time constraints and requirements of thecourse. However, knowing about E‑I is one way in which to individualize teaching.Basically,
this literature review asks if there is there a relationship between E‑I and L2 language learning.

日本大学歯学部

英語

Nihon University School of Dentistry
1‑8‑13 Kanda‑Surugadai, Chiyoda‑ku, Tokyo 101‑8310, Japan〒 101‑8310 東京都千代田区神田駿河台１‑８‑13(受理：2011年９月 30日)

1

日本大学歯学部紀要 39，1‑10，2011

E‑I plays a major role in not only first language acquisition but also in second language (L2)acquisition (Dewaele & Furnham,1999,p.529).Nation (2007,p.4)as part of his “Four Strands”
advocated talking in conversations as a way for receiving Meaning‑Focused Input and producing M eaning‑Focused Output. These two Strands are derived from Krashenʼs (1985) Input
Hypothesis and Swainʼs (1985)Output Hypothesis (Nation, 2007).
Lightbown & Spada (2006)wrote that many teachers are convinced that extraverted learners
who interact without inhibition in the L2 will be the most successful learners.I partiallybelievethis, so I try and talk with my students as much as I can. Usually, I talk with students thatexhibit extraverted tendencies.For these students,just talking and getting their message acrossis their goal.M any of my extraverted students just like to talk.It is easyto accommodate theirneed to communicate outside of class time without the pressures of the classroom.
With my introverted students, I spend considerable time explaining grammar points andcorrect pronunciation to them.These students take the time to say things correctly with goodpronunciation. When they are not pressured to speak, introverted students will speak slowly
and carefully, but what they usually say is grammatically accurate and with good pronunciation. I have also observed that in many cases, introverted students produce homework that isof a higher quality than extraverted students.
The way I modify my teaching depending on the individual student,suggests that there is aneed to study E‑I and its effects on learning. Many teachers whom I have observed teaching,
exploit the personalities of their students in academicallyadvantageous ways.The rationale forthis literature review on E‑I is to increase the power of language teachers to exploit theirstudentʼs personalities in ways beneficial to their learning both in class and away from class.

Rationale for the paper
The fields of personality and Individual Learner Differences (ID) are very broad areas ofstudy. ID have fascinated researchers in Second Language Acquisition (SLA) for a long timeand actually predate SLA as a field of inquiry itself (Ellis,2008).Dornyei & Skehan (2003)also
concluded that ID in L2 learning have generated the most consistent predictors of second
language success.
This paper is a literature review of selected papers that deal with E‑I and language learning.
When possible I have tried to search out papers that deal with the Japanese context as mycurrent teaching context is with Japanese learners. I have also tried to find papers that areconsidered turning points in the study and research of E‑I.The questions that I hope to answer
along the way are as follows:
1. How is E‑I measured and how reliable are these methods?
2. What are the definitions of E‑I found in the literature and how do these differ?
3. How can measures of E‑I be used in language teaching?

2

E‑I in SLA : a literature review

E‑I and its Relationship with CALP and BICS
Ellis (2008, p.673)reported that there are two major hypotheses with regard to the relationship of E‑I and L2 learning. The first hypothesis stated that extraverted learners do better inacquiring basic interpersonal communication skills (BICS).This is because extraverted learners
have more opportunity to practice,receive more input and thus become motivated and successful in L2 communication. The second hypothesis stated that introverted learners do better atdeveloping cognitive academic language proficiency (CALP). The reason might be that many
introverted learners spend more time reading,writing and trying to produce accurate language(Ellis, 2008).
BICS and CALP are terms coined by Cummins (1979) as two parts of a global language
proficiency factor. Cummins (2008) made these two distinctions “in order to draw educatorsʼ
attention to the timelines and challenges that second language learners encounter as theyattempt to catch up to their peers in academic aspects of the school language”(p.71).
There have been a few revisions to the definition of BICS/CALP, but basically Cummins(2008) referred to BICS as conversational fluency in a language. In other words, it is thelanguage necessary for daily life and includes informal conversations and interactions.It is fairto say that extraverted learners have little trouble with communication and thus BICS isreadily applicable to them.
Cummins (2008)referred to CALP as the studentsʼability to understand and express,in bothoral and written modes,concepts and ideas that are relevant to success.He was talking about
success in terms of school. Another way to put it is that CALP is the language necessary tofunction in the classroom by being able to understand and discuss classroom content.
While many researchers have used BICS/CALP as a way to describe the language proficiency of individual language learners, Cummins (2008) intended the primary use of BICS/
CALP as a way to understand and evaluate the language level of L2 learners.Of great interest
to E‑I research is that Cummins (1980)found that to acquire BICS took students on average 2
years whereas, CALP took at least 5 to 7 years.

Measuring Personality and E‑I
There is a plethora of E‑I related tests that are mainly used in health and psychologicalstudies. For example, the Sixteen Personality Factor Questionnaire (16PF) is described as a“self‑report assessment instrument, which enables clients to formulate personality models
useful in industrial/organizational applications, clinical settings, counseling, and research forpredicting human behavior”(IPAT,n.d.).A quick search on the Internet turned out many more
examples such as the Balanced Inventory of Desirable Responding (BIDR), Minnesota Multiphasic Personality Inventory(M M PI)and the Revised NEO Personality Inventory(NEO PI‑R).
Kezwer (1987)commented that a lack of uniformity of the results of personality tests may be3日本大学歯学部紀要 39，1‑10，2011

Table 1 Measures Used to Rate SubjectsʼDegree of E‑I(Kezwer, 19 87, pp.48‑49 )1. Teacher observations of three measures of sociability
2. Omnibus Personality Inventory
3. M arlowe‑Crowne Scale
4. Eysenck Personality Inventory
5. Teacher evaluations using an undescribed instrument
6. Observations by the subjectsʼteachers
7. Early School Personality Questionnaire
8. Personality‑Interest Testdue to the diversity of these tests used to measure E‑I.Kezwer also noted that inter‑reliability
correlations were not available among the various tests at that time. Although the tests wereof a similar type of self‑reporting questionnaire,they neither defined E‑I in the same way,norattempted to measure the same thing (p.49). Table 1 lists the personality tests that Kewzer
found in the literature.In addition to the larger varietyof personalitytests used in the research,
Kezwer also commented on the diversity of proficiency tests that are used to correlate with thepersonality tests (p.51). With the research comparing different personality tests with different
language proficiency tests to yield incomparable results, one can easily see why there is little
correlation with the E‑I research.
Ellis (2008)reported that E‑I is usually measured in language learning research by analyzing
responses to self‑report questions such as those in the Eysenck PersonalityQuestionnaire(EPQ)or the M yers Briggs Type Indicator (M BTI). Another measure that is used in many studies is
the Eysenck Personality Inventory (EPI). For many researchers, the EPI scales are the ʻ
goldstandardʼfor the measurement of E‑I (Dewaele & Furnham, 1999, p.514).
Busch (1982)praised the speed at which the EPI can be administered and easily scored.The
EPI has also has been used in many other studies which makes for a good basis for comparison.
Finally, compared with the EPQ, the EPI and has been well validated for Japanese learners(Busch,1982).The EPI created in 1963 is a psychological questionnaire that measures different
personality traits such as E‑I and neurosis (Robson,1994).A revised version of the EPI createdin 1974 is the EPQ and this measures amongst other things extraversion, psychoticism andneuroticism (Robson, 1994).
The majority of the research I have reviewed used the MBTI.The MBTI is a questionnairethat targets four personality dichotomies. These are E‑I, sensing‑intuition, thinking‑feeling,
and judging‑perceiving.Although the use of the EPI has been up until recently largely shunned
by SLA circles (Dewaele & Furnham, 1999, p.522), both the EPI and MBTI have been wellreceived as measurements for personality (Dewaele & Furnham, 1999, p.541). One of the
problems of using this multiplicity of measurement instruments,however,is that it is difficult
4

E‑I in SLA : a literature review

to draw general conclusions, as it is difficult to identify to what extent the constructs being
measured are the same or different (Kezwer, 1987, p.49).
On a related note,Dewaele(2005)explained that personality and particularly E‑I can be used
as a standalone measure of language learning in conjunction with more sensitive and appropriate research designs or be incorporated in the form of an ʼinterdisciplinaryʼmeasure. This
interdisciplinary measure would include collocated ID and psychological variables that are
spread out over personality psychology, applied linguistic and bilingualism which are focusedon interpersonal communication processes.

A chronology of Selected Research on E‑I
The Good Language Learner
No review on E‑I in SLA can be complete without mentioning the work of Naiman, N.,
Frohlich, M ., Stern, H.H. & Todesco, A. (1978) groundbreaking book The Good Language
Learner. It was groundbreaking at the time because it offered “a substantial empirical study
that was directly based on the experiences of good language learners”(Naiman et al.,1978,p.
viii).This study has been widely quoted in the literature and it might even have been instrumental in the misunderstanding of the link between E‑I and different types of language indicators(Dewaele & Furnham, 1999, p.520). In other words, the results of their study have negatively
influenced the perception of E‑I and language learning.
The aim of Naiman et al. ʼs (1978)study was to identify the predictors of success in second
language learning in the learnerʼs personality and other factors in order to portray what it was
to be a “good language learner”(Dewaele& Furnham,1999,p.520).Seventy‑two Canadian highschool students were administered a number of personality tests, among them the EPI. The
subjects were assessed using the IEA Listening Test of French Achievement and an Imitation
Test.The results for the E‑I portion of these tests found that there was no correlation between
extraversion and language learning. Dewaele and Furnham (1999) attributed the lack ofcorrelation between E‑I and language learning to their test designs that showed “unrealistic
expectations and insufficient understanding of the concept, before being judged irrelevant tolanguage learning”(p.509).
Itʼs fun to study at the Y‑M‑C‑ABusch (1982) proposed two questions from her study of the relationship between E‑I tendencies of Japanese students and their proficiency in EFL.The first question was the relationship between E‑I and standardized tests and the second was the relationship between E‑I andoral interview exams.She hypothesized that extraverts would do better at oral communication
because extraverts create opportunities to practice the language and obtain input,and also areable to increase motivation from successful experiences. These are opportunities to practice
more, create output, receive input and gain more success in communicating in the L2 (Ellis,
2008, p.674). These opportunities fit nicely with both Krashenʼs (1985) Input Hypothesis and5日本大学歯学部紀要 39，1‑10，2011

Swainʼs (1985, 1993)Comprehensive Output Hypothesis.
Buschʼ
s subjects were 80 junior college students and 105 adult learners who participated in a
YM CA standardized English test at the Kobe YMCA language school,completed the EPI andprovided information on a biodata form. Forty‑five of the 80 college students were thenrandomly chosen to participate in English oral interviews, rated by two evaluators. These
recorded interviews were rated two months later for comprehension, pronunciation, fluency,
and grammar.
Busch found no significant relationship between E‑I and the standardized English test (p.128).
She did find that there was a correlation between length of studyat the YMCA language schooland extraversion. She reasoned that it was likely that extraverted students were more likely
to continue at the YM CA than introverted students. Buschʼs second research question concerned the E‑I tendencies of Japanese students and their performance on oral interview tests(p.114).She found only a weak significant correlation between introverted students and pronunciation where introverted students had better pronunciation because they were less impulsive
than extroverted students (p.128).Ellis (2008)concluded that Buschʼ
s study fails to lend support
to the “hypothesis that introversion aids the development of academic language skills”(p.675).
Busch (1982)concluded, however, that the studies she looked at found “that introverts tend to
do better in high school and college”thus “support the view that introverts do better academically”(p.129).
Thorneʼs study of E‑I pairs
Thorne (1987) examined the mutual impact of extraverts and introverts on conversationstyle.Her test subjects were a group of 52 women who took the MBTI in order to divide theminto introverted and extraverted groups. The groups consisted of 26 extraverts and 26 introverts. These groups then formed speaking pairs and had two conversations to get acquainted
with each other.The three types of pairs that were created were of two types.Dispositionallysimilar pairs were made up of introverts with introverts (I/I),or extraverts with extraverts (E/E). Dissimilar pairs were made up of introverts with extraverts (I/E).
Schedules were arranged so that two extraverts and two introverts arrived at the samesession. The researchers made sure that the participants were not previously acquainted witheach other.The pairs were arranged so that each would converse with a dispositionally similar
and a dissimilar partner. These were analyzed and compared with each other. The pairing
produced a total of 52 conversations (13 E/E,13 I/I,and 26 I/E)(p.719).Her results found thatE/E pairs showed a wide range of topics and more claims of common ground and thus founda positive impact on conversation (p.725).Their conversations were more upbeat and expansive.
I/I pairs,however,engaged in focused problem talk.Their conversations were more serious andfocused. Thorne accounted for these differences in terms of the ability of E/E pairs to create
situations that have commonality (p.725). She pointed out that it is very difficult to have aconversation when one speaker is insistently upbeat and the other being serious (p.724).
6

E‑I in SLA : a literature review

Robsonʼs Japanese college students study
Robson reported in his 1994 doctoral dissertation that he undertook a small‑scale study offemale Japanese college students by measuring their personalities using the Japan‑specificYatabe/Guilford Personality Inventory (Robson, 1994,p.188)and comparing the results with avariety of language proficiency measures such as TOEFL scores.
Robson also obtaining measures of voluntary participation from oral English classes throughaudio recordings of his classes, which were then analyzed. Robson also based his study on
Cumminsʼ(1980)BICS/CALP construct.Robson found that generally,extraverted students who
were also sociallyactive and leaders were more likelyto participate in oral English classes thanintroverted students (p.142).
A study of Indonesian students learning English
Carrell, Prince and Astika (1996)looked at the relationship between personality types froma group of 76 Indonesian students and their academic performance in a semester‑long course.
The results of the M BTI were correlated with a battery of discrete‑point tests of reading
comprehension, vocabulary, grammar and writing. They found that the students were almost
evenly divided between extraversion and introversion,a finding similar to other studies (p.94).
Importantly,theyfound few direct relationships between E‑I and their performance on the tests(p.95).
These authors gave two reasons for the weak correlation between personality types andlanguage performance measures.The first was that personality preferences gave no indication
about studentʼ
s cognitive levels and maturity,which are related to the effectiveness with which
students apply cognitive resources (p.95). The second was that personality is not as robust an
indicator of relationships between language learning variables as a more salient ID such as
language aptitude (p.95).
Wakamotoʼs Japanese college student study
Wakamoto (2000)looked at the relationship between E‑I and language learning strategies of
254 female Japanese junior college students majoring in English. He employed the MBTI and
the Strategy Inventory for Language Learning (SILL) to see what Language Learning Strategies (LLS)the students used.The reason for his study was to find evidence for his hypothesisthat E‑I has a very important influence on learning English in Japanese secondary classrooms(p.71).Wakamoto argued that with class sizes in Japan of around 40 students per teacher,it isdifficult to take into account ID and LLS. Instead, teachers should be concentrating on theknowledge of how learners actually learn (p.71).
Wakamoto found a significant correlation of certain strategies with extraversion. Specifically, he found that there was a correlation between the LLS he labeled “functional practicestrategies” and “social‑affective strategies” with extraverted students (p.78). Wakamotodescribed “functional practice strategies”as practice that is focused on actual language use andnot form and “social‑affective strategies”as the mediation between people or control of oneʼs
7

日本大学歯学部紀要 39，1‑10，2011

affective domain (p.78). He found no significant correlation between LLS and introverted
students.

Conclusion
From the research articles that I have looked at,it is safe to say that personality traits,andin particular E‑I, have effects on language learning. This effect is not apparent in earlier
research and the failure to find a strong correlation between E‑I and language learningapparently discouraged research into this area. A major setback in continued personality andin particular E‑I research seems to have come from Naiman et al.ʼs (1978)poorly‑thought‑out
E‑I research design of E‑I (Dewaele, 2005). Naiman et al. (1978) in their study of a “goodlanguage learner”included E‑I in their research design but then later dismissed the use of the
EPI. The negative publicity generated by Naiman et al. (1978)may have led to the misunderstanding of E‑I in SLA circles as an independent variable (Dewaele, 2005, p.521).
Recent use of more sophisticated linguistic variables,covering not only written language but
also natural oral language,in conjunction with the EPI,has found that indeed the EPI was not
to blame for the lack of expected correlation reported by Naiman et al.(Dewaele,2005,p.522).
With more sensitive and appropriate research designs,extraversion has been found to be a goodpredictor of fluency in oral L2 production (Wakamoto, 2000;Dewaele, 2005). In other words
there has been some support that extraverted learners do better in acquiring BICS (Ellis,2008,
p.674).
Due to the enormous range of personality tests available, researchers had a hard timechoosing the appropriate instruments to use.Early research tended to use the instruments thatwere the cheapest or most expedient to use,but the cheapest and most widely used instruments
are not the most sensitive.Recent research has settled on a smaller group of personality tests
with results that are easier to compare.
The same cannot be said of introversion as research has yet to confirm that introverted
learners do better at developing CALP (Ellis, 2008). From the studies I looked at, both Busch(1982)and Carrell et al.(1996)failed to find a relationship between introversion and CALP.As
reported earlier, it takes more than double the time for students to acquire CALP than BICS
and so any studies on introversion and CALP will have to take this length of time into account.
It is imperative that future studies on introversion and CALP take a more longitudinal anddiachronic approach with an emphasis on more appropriate designs that are able to break down
the psychological constructs into their components.
Clearly more research needs to be done in the area of personality and language learning.
Personality is such a large and diverse field of study that it is inevitable that there have beensome problems in specifying it.Recent studies have finallyfound strong evidence that extraversion does have an effect on language learning and communicative language use, especially influency(Ellis,2008,p.676).Introversion,too,may have an effect on language learning,but more8

E‑I in SLA : a literature review

research and well designed experiments will need to be used to find a correlation. Instead of
focusing on ʻ
supertraitsʼlike introversion, research might take a more fine‑grained approachand focus on the ʻ
primary traitsʼthat make up these ʻsupertraitsʼ. Ellis (2008) summarized asfollows “the role of personality needs to be examined in terms of how traits such as E‑I
influence the way that learners process language”(p.677).
References
Busch, D. (1982) Introversion‑extraversion and the EFL proficiency of Japanese students. Language
Learning, 32, 109 ‑132
Carrell,P.,Prince,M .,& Astika,G.(1996)Personality types and language learning in an EFL context,
Language Learning, 46, 75‑99
Cummins, J. (1980) Psychological assessment of immigrant children : Logic or intuition? Journal ofMultilingual and Multicultural Development, 1, 97‑111
Cummins,J.(2008)BICS and CALP : Empirical and theoretical status of the distinction.In B.Street,&
N.H. Hornberger (Eds.), Encyclopedia of Language and Education, 2nd ed., Vol. 2 : Literacy (pp.
71‑83). New York : Springer Science＋Business Media LLC
Dewaele, J.M . (2005)Investigating the psychological and emotional dimensions in instructed language
learning : Obstacles and possibilities. The Modern Language Journal, 89, 367‑380
Dewaele,J.M .& Furnham,A.(1999)Extraversion :The unloved variable in applied linguistic research.
Language Learning, 49, 509 ‑544
Dornyei, Z., & Skehan, P. (2003)Individual differences in second language learning.In C.J.Doughty&
M.H.Long (Eds.),The handbook of second language acquisition (pp.589 ‑630).Malden,MA : Blackwell
Ellis,R.(2008)The Study of Second Language Acquisition (2nd ed.).Oxford : Oxford University Press
IPAT (n.d.)IPAT ‑The 16PF Questionnaire.Retrieved from http://www.ipat.com/about/16pf/Pages/
default.aspx
Krashen, S.D. (1985)The input hypothesis. London : Longman
Kezwer,P.(1987)The extroverted vs.the introverted personality and second language learning.TESL
Canada Journal, 5, 45‑58
Lightbown,P.M .,& Spada,N.(2006)How languages are learned (3rd ed.).Oxford : Oxford University
Press
Moody,R.(1988)Personality preferences and foreign language learning.The Modern Language Journal,
72, 389 ‑401
Naiman, N., Frohlich, M ., Stern, H.H. & Todesco, A. (1978) The Good Language Learner. Toronto :Modern Language Centre, Ontario Institute for Studies in Education
Nation, P. (2007)The four strands. Innovation in Language Learning and Teaching, 1, 2‑13
Robson, G.L. (1994) Relationships between personality, anxiety, proficiency and participation (Doctoral
dissertation). Temple University Japan. (UMI No.9512864)
Swain, M. (1985) Communicative competence: Some roles of comprehensive input and comprehensive
output in its development. Rowley, M A : Newbury House
Swain, M. (1993) The output hypothesis: Just speaking and writing arenʼ
t enough. The Canadian9日本大学歯学部紀要 39，1‑10，2011

Modern Language Review, 50, 158‑164
Thorne,A.(1987)The press of personality: A study of conversations between introverts and extraverts. Journal of Personality and Social Psychology, 53, 718‑726
Wakamoto,N.(2000)Language learning strategy and personality variables: Focusing on extroversion
and introversion. International Review of Applied Linguistics in Language Teaching, 38, 71‑8110