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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Is Big Five better than MBTI? A personality computing challenge using Twitter data</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Fabio Celli</string-name>
          <email>celli@fbk.eu</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Bruno Lepri</string-name>
          <email>lepri@fbk.eu</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>FBK - MobS and Profilio Company</institution>
          ,
          <addr-line>Trento</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>FBK - MobS</institution>
          ,
          <addr-line>Trento</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>English. Personality Computing from text has become popular in Natural Language Processing (NLP). For assessing gold-standard personality types, Big5 and MBTI are two popular models but still there is no comparison of the two in personality computing. With this paper, we provide for the first time a comparison of the two models from a computational perspective. To do that we exploit two multilingual datasets collected from Twitter in English, Italian, Spanish and Dutch.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1 Introduction</title>
      <p>
        The last decade has been characterized by the
rise of personality computing in Natural
Language Processing (NLP)
        <xref ref-type="bibr" rid="ref33">(Vinciarelli and
Mohammadi, 2014)</xref>
        : for example, several works have
dealt with the automatic prediction of personality
traits of authors from different pieces of text they
wrote in emails, blogs or social media
        <xref ref-type="bibr" rid="ref13 ref16 ref26">(Mairesse
et al., 2007; Iacobelli et al., 2011; Schwartz et
al., 2013)</xref>
        <xref ref-type="bibr" rid="ref25">(Rangel Pardo et al., 2015)</xref>
        .
Personality computing is also broadening its application
to many fields in academia as well as in
industry, including security
        <xref ref-type="bibr" rid="ref11">(Golbeck et al., 2011)</xref>
        ,
human resources
        <xref ref-type="bibr" rid="ref30">(Turban et al., 2017)</xref>
        , advertising
        <xref ref-type="bibr" rid="ref27 ref4">(Celli et al., 2017)</xref>
        and deception detection
        <xref ref-type="bibr" rid="ref9">(Fornaciari et al., 2013)</xref>
        . Historically, there are two
popular but very different psychological tests to
asses personality: (i) the Big Five
        <xref ref-type="bibr" rid="ref15 ref6 ref7">(Costa and
McCrae, 1985; Costa and McCrae, 2008)</xref>
        , which is
widely accepted in academia, and (ii) the Myers
Briggs Type Indicator (MBTI)
        <xref ref-type="bibr" rid="ref17 ref28">(Myers and Myers,
2010)</xref>
        , which is very popular and widely used in
industry. The Big Five model defines
personality along 5 bipolar scales: Extraversion (sociable
vs. shy); Emotional Stability (secure vs.
neurotic); Agreeableness (friendly vs. ugly);
Conscientiousness (organized vs. careless);
Openness to Experience (insightful vs.
unimaginative). In contrast, the MBTI defines 4 binary
classes that combines into 16 personality types:
Extraversion/Introversion, Sensing/Intuition,
Perception/Judging, Feeling/Thinking. Correlation
analyses of the personality measures showed
that Big Five Extraversion was correlated with
MBTI Extraversion-Introversion, Openness to
Experience was correlated with Sensing-Intuition,
Agreeableness with Thinking-Feeling and
Conscientiousness with Judging-Perceiving
        <xref ref-type="bibr" rid="ref10">(Furnham et
al., 2003)</xref>
        . A reason for the recently gained
popularity of MBTI is the fact that it is easier to
collect gold-standard labelled data about MBTI than
about Big Five, as an MBTI type is a 4-letter
coding (e.g., INTJ) that could be retrieved with
simple queries. In a field like personality computing,
where data is costly and difficult to collect, this is
an enormous advantage.
      </p>
      <p>In this paper we address the question whether it is
easier to predict Big Five or MBTI classes with a
machine learning approach. To do so, we collect
two Twitter datasets in English, Italian, Dutch and
Spanish, one annotated with the Big Five
personality types and one with MBTI. We believe that this
work will be useful for the scientific community
of personality computing to better understand the
heuristic power of the two models when applied to
machine learning tasks.</p>
      <p>The paper is structured as follows: in the next
section we provide an overview of related works in
the field of personality computing in NLP, in
Section 3 we describe the datasets we used, in Section
4 we report the results of our experiments and in
Section 5 we draw some conclusions.
2</p>
    </sec>
    <sec id="sec-2">
      <title>Related Work</title>
      <p>
        Brief overview of personality computing The
research in personality computing from text begun
more than a decade ago with few pioneering works
recognizing personality traits (Big Five traits)
from blogs
        <xref ref-type="bibr" rid="ref18">(Oberlander and Nowson, 2006)</xref>
        and
self presentations
        <xref ref-type="bibr" rid="ref16">(Mairesse et al., 2007)</xref>
        . Other
related fields have developed in the same years,
like personality computing from multimodal and
social signals, such as recorded meetings
        <xref ref-type="bibr" rid="ref19">(Pianesi
et al., 2008)</xref>
        . In that period the research on MBTI
was limited to find correlates between
personality types and behavioral expectations, such as job
preference
        <xref ref-type="bibr" rid="ref5">(Cohen et al., 2013)</xref>
        . Thus, MBTI
was marginally used for personality computing
until 2015
        <xref ref-type="bibr" rid="ref15 ref7">(Luyckx and Daelemans, 2008)</xref>
        ; while
many works demonstrated the validity of Big Five
for the automatic prediction of personality from
different sources, including Twitter
        <xref ref-type="bibr" rid="ref23">(Quercia et
al., 2011)</xref>
        <xref ref-type="bibr" rid="ref20 ref21">(Pratama and Sarno, 2015)</xref>
        <xref ref-type="bibr" rid="ref22">(Qiu et al.,
2012)</xref>
        . The most common features used by
researchers to perform such tasks were extracted
from text, such as sentiment
        <xref ref-type="bibr" rid="ref14 ref2 ref3 ref31 ref5 ref9">(Basile and Nissim,
2013)</xref>
        , Part of Speech (PoS) tags,
psycholinguistic tags (LIWC)
        <xref ref-type="bibr" rid="ref17 ref28">(Tausczik and Pennebaker, 2010)</xref>
        and from metadata, such as number of followers,
density of subject’s network, hashtags, Likes and
profile pictures. The rise of personality computing
by means of the Big Five model brought fruitful
collaborations between the communities of
computer science and personality psychology
        <xref ref-type="bibr" rid="ref1">(Back
et al., 2010)</xref>
        , and very interesting findings came
out: for example that several personal
characteristics extracted from social media profiles such as
education, religion, marital status and the number
of political preferences have really high
correlations with personality types
        <xref ref-type="bibr" rid="ref14">(Kosinski et al., 2013)</xref>
        ,
or that popular users in social media are both
extroverts and emotionally stable as well as high in
Openness, while influential ones tend to be high in
      </p>
      <sec id="sec-2-1">
        <title>Conscientiousness (Quercia et al., 2012).</title>
        <p>
          Overview of datasets The scarcity of data
annotated with gold standard personality labels,
difficult and costly to collect, was a major problem
and the few large datasets available
(MyPersonality, about 75K users, and Essays, about 2K users)
soon became standard benchmarks
          <xref ref-type="bibr" rid="ref3 ref9">(Celli et al.,
2013)</xref>
          . These available datasets covered mainly
English language, while all the other datasets were
much smaller, around 200 or 300 instances. In this
scenario a dataset of 1500 instances collected by
means of a simple Twitter search came out, and
it was in English and annotated with MBTI labels
          <xref ref-type="bibr" rid="ref20 ref21">(Plank and Hovy, 2015)</xref>
          . This demonstrated that
MBTI labels are very common and easy to retrieve
from Twitter, unlike Big Five labels. Soon
thereafter, TwiSty came out
          <xref ref-type="bibr" rid="ref32">(Verhoeven et al., 2016)</xref>
          ,
a multilanguage dataset of 17K instances
annotated with MBTI and including Italian, Dutch,
Portuguese, French and Spanish.
        </p>
        <p>
          State of the art The MBTI model formalizes
personality types as classes, while Big Five as
scores. Despite this, works in computer science
and computational linguistics split between those
who use scores
          <xref ref-type="bibr" rid="ref11">(Golbeck et al., 2011)</xref>
          and those
who turn Big Five scores into binary classes in
order to have a better control on class distribution
and easier-to-interpret prediction tasks
          <xref ref-type="bibr" rid="ref16">(Mairesse
et al., 2007)</xref>
          <xref ref-type="bibr" rid="ref27">(Segalin et al., 2017)</xref>
          . In particular,
Mairesse et al. obtained an average of 57%
accuracy in the prediction of Big Five classes using
the LIWC psycholinguistic features, also reporting
that Openness to Experience was the easiest trait to
model. Verhoeven et al.
          <xref ref-type="bibr" rid="ref31">(Verhoeven et al., 2013)</xref>
          obtained a 72% of F-measure in the prediction of
Big Five using trigrams and ensemble methods in
a small Facebook dataset trained on a larger
essays dataset. In a following study, Verhoeven et
al.
          <xref ref-type="bibr" rid="ref32">(Verhoeven et al., 2016)</xref>
          obtained an average of
63.8% of F-measure in the prediction of MBTI on
Twitter in multiple languages using word and
characters n-grams. Again, Farnadi et al.
          <xref ref-type="bibr" rid="ref8">(Farnadi et
al., 2013)</xref>
          obtained an average accuracy of 58.6%
to predict Big Five classes on the same dataset
using mostly metadata. Finally, Plank and Hovy
          <xref ref-type="bibr" rid="ref20 ref21">(Plank and Hovy, 2015)</xref>
          used words and Twitter
metadata to predict Extraversion/Introversion and
Feeling/Thinking with 72% and 61% of accuracy,
respectively. They reported that the best
performing features are the linguistic ones.
        </p>
        <p>The different settings and datasets used by
previous works in the field makes it impossible to
compare the results. Here, we aim to fill this gap.
3</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Datasets</title>
      <p>
        We collected from Twitter two multilingual
datasets, of 900 users each, one annotated with
MBTI and one with Big Five. First we collected
the Big Five set by means of queries with
Twitter advanced search1, retrieving the results of
different Big Five tests, ranging from the short
10items test to the 44-items test. The language of the
tweets were English, Italian, Spanish and Dutch,
so we replicated the language distribution in the
MBTI set using a portion of TwiSty
        <xref ref-type="bibr" rid="ref32">(Verhoeven
et al., 2016)</xref>
        and Plank’s corpus
        <xref ref-type="bibr" rid="ref20 ref21">(Plank and Hovy,
2015)</xref>
        . The details about language distributions
are reported in Figure 1.
      </p>
      <p>As expected there are many more tweets
containing the results of the MBTI with respect to the
Big Five. We use a concatenation of all tweets of
a user, and a limit to 40 tweets per user in order
to balance those who have too many tweets those
that have few. In the end we used two comparable
datasets with 900 users each, 265K words in the
Big Five one and 290K words in the MBTI one.
The classes are balanced in the Big Five set, as we
obtained them with a median split from the
original scores, on the contrary in the MBTI set there
is a strong imbalance in the distribution of
Sensing/Intuition and Feeling/Thinking, reported also
in Plank’s corpus. In the experiments, described
in the next section, we balance the classes of both
datasets and test different combinations of the
features to evaluate the performance of machine
leaning algorithms in the prediction of classes derived
from the two different personality models.</p>
      <sec id="sec-3-1">
        <title>1https://twitter.com/search-advanced</title>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>Experiments, Results, Discussion and</title>
    </sec>
    <sec id="sec-5">
      <title>Limitations</title>
    </sec>
    <sec id="sec-6">
      <title>Experimental settings We compared the per</title>
      <p>formance of algorithms for the prediction of Big
Five and MBTI classes in 9 binary classification
tasks. To do so, we used the following features:
- Character n-grams (1000 features): we
extracted from tweets 1000 characters bi-grams and
tri-grams with a minimum frequency of 3. We did
not remove stopwords and punctuation;</p>
      <p>- LIWC match ratio (68 features): we computed
the ratio of matches of the words in the LIWC
dictionaries in all the four languages. LIWC
provides mapping from words to 68 psycholinguistic
categories, including words about others, self,
space, time, society, family, friendship, sex, and
functional words, among others;</p>
      <p>
        - Metadata (10 features): this feature set
includes the followers/following ratio,
favorite/tweets ratio, listed/tweets ratio, link color,
text color, border color, background color,
hashtag/words ratio, retweet ratio, whether the profile
picture is the default one or not. As feature
selection procedure we used a subset selection
algorithm
        <xref ref-type="bibr" rid="ref12">(Hall and Smith, 1998)</xref>
        that reduces the
degree of redundancy. We balanced the classes
assigning weights to the instances in the data
so that each class has the same total weight.
For the classification we compared SVMs and a
meta-classifier that automatically finds the best
performing algorithm for the task
        <xref ref-type="bibr" rid="ref29">(Thornton et al.,
2013)</xref>
        . As evaluation setting we used a 10-fold
cross validation, as metric we reported accuracy
and averages. For the maximum comparability
we also reported the average on the Big Five four
traits correlated with MBTI (avg4): extraversion,
openness, agreableness and conscientiousness.
Results and discussion Results reported in
Table 1 show that, on average, SVMs have higher
performance in the prediction of MBTI classes
with respect to Big Five, but there is much
variability in the prediction of Big Five traits. In
particular, we obtained very good performances
for Emotional Stability and Agreeableness using
a SVMs with polynomial kernel and Random Sub
Spaces respectively, but poor with simple SVMs,
indicating that the space is not linearly
separable. On the contrary, the predictions of the MBTI
seems to be more stable, in contrast to the results
of Plank and Hovy. We suggest that this different
trait
extr.
stab.
agree.
consc.
open.
avg4
avg
E-I
S-N
F-T
P-J
avg
is interesting to note that the reference to others is
the best feature for the prediction of Big Five
Extraversion and first person pronouns for the
prediction of Emotional Stability/Neuroticism.
We
explain the predictive power of words about death
for Agreeableness and Conscientiousness with the
fact that this feature is correlated to the negative
poles of these traits.
      </p>
      <p>The presence of different
languages might affect negatively the performance
so we ran an experiment using only English (650
users for each set).</p>
      <p>Results, reported in Table 2, show that the effect of
language variety is minimum, given that English
is the most represented language in the datasets. It
is interesting to note the changes in the best
features: hashtag ratio is in English the best feature
for Extraversion Big Five, while in the previous
experiment it was the best feature for
Extraversion MBTI. Here the best feature for Extraversion
MBTI is anger, that is a clue for the negative class
of this trait: Introversion. It is also interesting to
note that words about feelings become in English
the best feature for Agreeableness, although the
performance decreases a little bit with respect to
the experiment with all languages.
trait
extr.
stab.
agree.
consc.
open.
avg4
avg
E-I
S-N
F-T
P-J
avg</p>
      <p>Limitations In order to compare the two
personality models, we forced the Big Five outcome,
originally scores, into classes. This is one of the
reasons why it is more difficult to predict Big Five
classes than MBTI, but it is interesting to note that
the performance of some Big Five traits can be
boosted using non-linear models. Another
limitation is related to the fact that we collected
different users in the two datasets, with the risk to
have some individuals in one dataset or the other
that are easier to classify. In any case, it is
impossible to collect data of the same users
annotated with both MBTI and Big Five with Twitter
queries, this is something that could be done only
with a costly data collection effort, that we hope
future work will do.
5</p>
    </sec>
    <sec id="sec-7">
      <title>Conclusion</title>
      <p>In this paper we provide for the first time a
comparison of Big Five and MBTI from a personality
computing perspective. To do so we use two
multilingual Twitter datasets, one annotated with Big
Five classes and one with MBTI classes. For the
first time, we provide an evidence that algorithms
trained on MBTI could have better performances
than trained on the Big Five, although the Big Five
is much more informative and has great variability
in performance depending also on the algorithm
used for the prediction. We let available the files
used for the experiments2, in order to grant the
replicability or improvement of the results.</p>
      <sec id="sec-7-1">
        <title>2http://personality.altervista.org/fabio.htm</title>
      </sec>
    </sec>
    <sec id="sec-8">
      <title>Acknowledgments</title>
      <p>The work of Fabio Celli and Bruno Lepri was
partly funded by EIT Digital by City Enabler for
Digital Urban Services (CEDUS) and by EIT
Distributed Ledger Invoice (DLI).</p>
    </sec>
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