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  <front>
    <journal-meta>
      <journal-title-group>
        <journal-title>ACM Conference on Recommender Systems (RecSys). August</journal-title>
      </journal-title-group>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Personality Traits and Music Genre Preferences: How Music Taste Varies Over Age Groups</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Bruce Ferwerda∗</string-name>
          <email>bruce.ferwerda@jku.at</email>
          <email>bruce.ferwerda@ju.se</email>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Marko Tkalcic</string-name>
          <email>marko.tkalcic@unibz.it</email>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Markus Schedl</string-name>
          <email>markus.schedl@jku.at</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Music, Personality, Recommender Systems, User Modeling, Age</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Dep. of Computational Perception, Johannes Kepler University</institution>
          ,
          <addr-line>Altenberger Strasse 69, 4040, Linz</addr-line>
          ,
          <country country="AT">Austria</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Dierences</institution>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Faculty of Computer Science, Free University of Bozen-Bolzano</institution>
          ,
          <addr-line>Piazza Domenicani 3, I-39100, Bozen-Bolzano</addr-line>
          ,
          <country country="IT">Italy</country>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>School of Engineering, Jo ̈nko ̈ping University</institution>
          ,
          <addr-line>P.O. Box 1026, SE-551 11, Jo ̈nko ̈ping</addr-line>
          ,
          <country country="SE">Sweden</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2017</year>
      </pub-date>
      <volume>31</volume>
      <issue>2017</issue>
      <abstract>
        <p>Personality traits are increasingly being incorporated in systems to provide a personalized experience to the user. Current work focusing on identifying the relationship between personality and behavior, preferences, and needs oen do not take into account dierences between age groups. With music playing an important role in our lives, dierences between age groups may be especially prevalent. In this work we investigate whether dierences exist in music listening behavior between age groups. We analyzed a dataset with the music listening histories and personality information of 1415 users. Our results show agreements with prior work that identied personality-based music listening preferences. However, our results show that the agreements we found are in some cases divided over dierent age groups, whereas in other cases additional correlations were found within age groups. With our results personality-based systems can provide beer music recommendations that is in line with the user's age.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>CCS CONCEPTS</title>
      <p>•Information systems ! Recommender systems; •Human-centered
computing ! User models; User studies;</p>
    </sec>
    <sec id="sec-2">
      <title>INTRODUCTION</title>
      <p>
        Personality has shown to be a stable construct over time, and
reects the coherent paerning of one’s aect, cognition, and desires
(goals) as it leads to behavior [
        <xref ref-type="bibr" rid="ref24">24</xref>
        ]. is stability and coherency of
personality has shown to be useful for systems to infer users’
preferences and to provide personalized experiences to users (e.g., [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]).
Hu &amp; Pu [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ] showed that personality-based personalized systems
have an advantage over personalized systems not incorporating
personality information in terms of increased users’ loyalty towards
the system and decreased cognitive eort.
      </p>
      <p>
        e relationships between personality traits and users’ behavior
preferences and needs are increasingly being investigated (e.g.,
health [
        <xref ref-type="bibr" rid="ref17 ref26">17, 26</xref>
        ], education [
        <xref ref-type="bibr" rid="ref2 ref21">2, 21</xref>
        ], movies [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], music [
        <xref ref-type="bibr" rid="ref10 ref14 ref27 ref8 ref9">8–10, 14, 27</xref>
        ]).
ese studies normally analyze their sample as a whole and do
not consider dierences based on age groups. Arne [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] showed
that especially those in their adolescence and emerging adulthood
phases experience a heightened chance of ”storm and stress” 1 in
which they try to nd their place in society. Hence, dierences
may occur in behavior, preferences, and needs throughout dierent
phases in life.
      </p>
      <p>
        To investigate the relationship between personality and music
genre preferences over dierent age groups, we used a subset of
the myPersonality dataset. Next to users’ personality scores, this
subset consist of the listening history of Last.fm (an online music
streaming service) 2 users. By analyzing the listening histories
of 1068 users in relation to their personality and age, we found
important dierences across age groups. Our insights may help
to inform personalized music systems. For example,
personalitybased music recommender systems can improve their cold-start
recommendations (e.g., [
        <xref ref-type="bibr" rid="ref28 ref5">5, 28</xref>
        ]) by beer knowing which music
genres to recommend to their users of dierent age groups.
2
      </p>
    </sec>
    <sec id="sec-3">
      <title>RELATED WORK</title>
      <p>
        Currently, there are two dierent personality related research
directions focusing on: 1) personality-based personalization (e.g.,
health [
        <xref ref-type="bibr" rid="ref17 ref26">17, 26</xref>
        ], education [
        <xref ref-type="bibr" rid="ref2 ref21">2, 21</xref>
        ], movies [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ], music [
        <xref ref-type="bibr" rid="ref10 ref14 ref27 ref8 ref9">8–10, 14, 27</xref>
        ])
and 2) implicit personality acquisition from user-generated content
(e.g., Facebook [
        <xref ref-type="bibr" rid="ref12 ref16">12, 16</xref>
        ], Twier [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ], Instagram [
        <xref ref-type="bibr" rid="ref11 ref13">11, 13</xref>
        ], and fusing
information [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ]). For example, in the area of personality-based
personalization Ferwerda et al. [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ] looked at dierences in how
users browse for music (i.e., browsing music by genre, activity, or
mood) in an online music streaming service. Chen, Wu, &amp; He [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]
investigated diversity preferences in movie recommendations. In
the area of implicit personality acquisition research mainly focuses
on user-generated content of users’ social media accounts.
ercia et al. [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ] found that how users behave on Twier consist of
cues to predict their personality. Similarly, Golbeck, Robles, &amp;
Turner [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ] were able to develop a personality predictor based on
the characteristics of a user’s Facebook account.
      </p>
      <p>
        Current personality-based research does not take into account
dierences between age groups. However, Arne [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ] notes that
especially those in their adolescence and emerging adulthood phases
may show deviant behavior. With music been shown to play an
important role in our lives by providing support for a whole range
1Storm-and-stress is a term rst coined by Hall [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ] to refer to a period in life in which
people experience turmoil and diculties.
2hp://www.last.fm/
of daily activities we engage in (e.g., sports, studying, sleeping) [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ],
dierences (e.g., listening behavior, preferences, and needs) across
age groups may especially be prevalent.
      </p>
      <p>In this work we analyze a dataset of an online music streaming
service consisting of the total listening history of their users. With
this dataset we investigate whether dierences in music listening
behavior exist.
3</p>
    </sec>
    <sec id="sec-4">
      <title>METHOD</title>
      <p>In order to investigate the relationship between personality and
music genre preferences across age groups in an online music
streaming service, we made use of the myPersonality dataset. 3 e dataset
originates from a popular Facebook application (”myPersonality”)
that is able to record psychological and Facebook proles of users
that used the application to take psychometric (e.g., personality,
attitudes, skills) tests. e dataset contains over 6 million test results,
with over 4 million Facebook proles. Users’ personality in the
myPersonality application was assessed using the Big Five
Inventory to measure the constructs of the ve factor model: openness,
conscientiousness, extraversion, agreeableness, and neuroticism.</p>
      <p>We only used the subset of the myPersonality dataset that
contains the music listening history of Last.fm users (i.e., play-count
of artists that a user listened to) and the day of birth in order to
calculate their age. e subset consists of users’ complete
listening histories (i.e., from the moment they started to use Last.fm)
until April 27 (2012). We complemented the dataset by adding the
listening events of each user until December 18 (2016) by using
the Last.fm API. 4 A total of 1066 Last.fm users with 40 million
listening events from 101 countries are represented in the subset.</p>
      <p>
        e 1066 Last.fm users were split into three dierent age groups
according to the primary life stages [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]: adolescence (age: 12-19),
young adulthood (age: 20-39), and middle adulthood (age: 40-65).
Having the day of birth of the 1066 Last.fm users as well as their
complete listening history (with listening date), we could traceback
users’ age when listened to a certain song. Hence, users could fall
into multiple age groups, which resulted in a sample size bigger
than the original sample. e nal dataset consists of 1479 Last.fm
users divided over three age groups (adolescence: n =581, young
adulthood: n =850, middle adulthood: n =48).
      </p>
      <p>
        rough the Last.fm API, we crawled additional information
about the artists by using the ”Artist.getTopTags” endpoint. is
endpoint provided us with all the tags that users assigned to an
artist, such as instruments (“guitar”), epochs (“80s”), places (“Chicago”),
languages (“Swedish”), and personal opinions (“seen live” or “my
favorite”). Tags that encode genre or style information were ltered
for each artist. e ltered tags were then indexed by a dictionary
of 18 genre names retrieved from Allmusic. 5 For each user in an
age group, the artists that were listened to were aggregated by
the indexed genre with their play-count. e genre play-count for
each user was then normalized to represent a range of rϵ[
        <xref ref-type="bibr" rid="ref1">0,1</xref>
        ], this
in order to be able to compare users with dierences in the total
amount of listening events.
3hp://mypersonality.org/
4hp://www.last.fm/api
5hp://www.allmusic.com
For the analysis we ltered out users with zero play-counts (users
who registered, but did not make use of Last.fm) and people
listening to less than ve dierent artists. is le us with a total of 1068
users (adolescence: n =472, young adulthood: n =563, middle
adulthood: n =33). e normalized genre play-counts by the dierent
age groups are shown in Figure 1.
      </p>
      <p>To investigate music listening dierences between personality
traits, Spearman’s correlation was computed between personality
traits and the genre play-count to assess the relationship of
personality and genre preferences. Alpha levels were adjusted using the
Bonferroni correction to limit the chance on a Type I error. e
reported signicant results adhere to alpha levels of p &lt;.001 (see
Table 1). e results of music genre preferences per personality
trait per age groups are discussed in the following sections.
4.1</p>
    </sec>
    <sec id="sec-5">
      <title>Openness</title>
      <p>Adolescence (age: 12-19). For the adolescence group, several
positive correlations were found with music genres: New Age (r =.142),
Blues (r =.130), Country (r =.117), World (r =.114), Folk (r =.230),
Jazz (r =.139), Vocal (r =.132), and Alternative (r =.131). ose
scoring high on the openness scale show in general higher listening
behavior to these music genres.</p>
      <p>Young adulthood (age: 20-39). For the young adulthood group,
we found the same kind of positive correlations with music
genres: New Age (r =.105), Blues (r =.167), Country (r =.126), World
(r =.217), Folk (r =.231), Jazz (r =.106), Vocal (r =.170), and
Alternative (r =.116). An additional positive correlation was found with
Electronic (r =.106), and a negative correlation with Rock (r =-.104)
indicating that those scoring high on openness tend to listen less
to Rock music in this age group. Next to Folk music, a stronger
correlation was found for World music as well.</p>
      <p>Middle adulthood (age: 40-65). When those scoring high on
openness reach middle adulthood, their variation of listening to
music genres shrinks signicantly, but the strength of the correlations
increases. We found positive correlations with Blues (r =.358) as
well as with Folk (r =.368) music. Indicating that although the
variation gets less, the music genre preferences for middle adulthood
becomes more prominent.
Adolescence (age: 12-19). ose scoring high on
conscientiousness in the adolescence group show mainly negative correlations
with the listened music genres: Reggae (r =-.102), Punk (r =-.130),
and Alternative (r =-.108). e results indicates that for this age
group, conscientious users listen less to these music genres.
Young adulthood (age: 20-39). Negative correlations were also
found between music genres and conscientiousness for the young
adulthood group. Although the Punk (r =-.103) and Alternative
(r =-.108) music genre is in line with the adolescence group, instead
of Reggae, this group listens less to Folk (r =-.114) music.</p>
      <sec id="sec-5-1">
        <title>Middle adulthood (age: 40-65). We found two correlations for</title>
        <p>the middle adulthood group: Jazz (r =.510) and Alternative (r =.507).
Both correlation coecients show high eects between
conscientiousness and the music genres.
4.3</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>Extraversion</title>
      <p>Adolescence (age: 12-19). e adolescence group show
negative correlations with Classical (r =-.136), World (r =-.102), Punk
(r =-.111), and Metal (r =-.148). A positive correlation was found
with R&amp;B (r =.106). e results indicate that extraverts in their
adolescence phase listen less to Classical, World, Punk, and Heavy
Metal music. However, the in general listen to more R&amp;B.</p>
      <sec id="sec-6-1">
        <title>Young adulthood (age: 20-39). For those scoring high on ex</title>
        <p>traversion and fall in the young adulthood group show negative
correlations with Rock (r =-.102), New Age (r =-.184), Classical
(r =-.146), and Heavy Metal (r =-.126). A positive correlation was
found with Rap (r =.108) music.</p>
      </sec>
      <sec id="sec-6-2">
        <title>Middle adulthood (age: 40-65). e middle adulthood group</title>
        <p>of the extraverts show a positive correlation with R&amp;B (r =.326)
and a negative correlation with Heavy Metal (r =-.339).
4.4</p>
      </sec>
    </sec>
    <sec id="sec-7">
      <title>Agreeableness</title>
      <p>Adolescence (age: 12-19). e adolescence group show only a
positive correlation with agreeableness for Folk (r =.101) music.
is indicates that agreeable users show in this age group show a
preference for Folk music.</p>
      <p>Young adulthood (age: 20-39). A more varied music preference
is shown for the young adulthood group. Positive correlations were
found for Country (r =.184), Folk (r =.110), and Pop (r =.194) music.
A negative correlation was found for Heavy Metal (r =-.105) music.
Agreeable users in their young adulthood phase seem to prefer to
listen to Country, Folk, and Pop, but less to Heavy Metal music.</p>
      <sec id="sec-7-1">
        <title>Middle adulthood (age: 40-65). e middle adulthood group</title>
        <p>show a negative correlation with Heavy Metal (r =-.339) music,
which indicates that their preference to listen to Heavy Metal goes
down when reaching the age of middle adulthood.
4.5</p>
      </sec>
    </sec>
    <sec id="sec-8">
      <title>Neuroticism</title>
      <p>Adolescence (age: 12-19). Neurotics in their adolescence phase
show positive correlations with Punk (r =.101) as well as with
Alternative (r =.129) music, indicating an increase preference for
these music genres.</p>
      <p>Young adulthood (age: 20-39). Only a positive correlation with
Alternative (r =.137) was found in the young adulthood group.
Middle adulthood (age: 40-65). For the middle adulthood group,
music preferences seem to switch. A positive correlation was found
with Heavy Metal (r =.372) and a negative correlation was found
with Blues (r =-.552).
5</p>
    </sec>
    <sec id="sec-9">
      <title>DISCUSSION</title>
      <p>
        Our results show that there are dierences in music listening
behavior between personality traits, and that these dierence can
be further broken down by age groups. Overall, our results show
that users in their adolescence and young adulthood phases show
most variation in their music listening behavior. Not only does
the variation become much less when reaching middle adulthood,
the correlation strength increase signicantly. is indicates that
music preferences of the middle adulthood group becomes more
established, which is in line with the storm-and-stress argument [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ].
      </p>
      <p>
        e openness trait shows most variation in listening to dierent
music genres amongst the personality traits. is is in line with one
of the few works that investigated the relationship between
personality traits and music listening behavior [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ]. However, what their
ndings do not show is that there are dierences when considering
age groups. For example, the addition of a preference for Electronic
music in the young adulthood group.
      </p>
      <p>
        Also the conscientiousness trait shows agreement with prior
work [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ]. However, additional unique correlations were able to
be identied when taking dierent age groups into account. Our
results show that the adolescence group shows an additional
negative correlation with Reggae, the young adulthood group shows an
additional correlation with Folk music, and the middle adulthood
group shows an additional positive correlation with Jazz music.
      </p>
      <p>
        Our results on extraversion show agreements with prior works [
        <xref ref-type="bibr" rid="ref20 ref23">20,
23</xref>
        ] as well. However, what the results of prior works do not show
is that there is a division based on age. For example, our results
show that the positive correlation of R&amp;B and Rap, dier across age
groups. e adolescence and middle adulthood group show positive
correlations only with R&amp;B, whereas only a positive correlation
with Rap was found with the young adulthood group.
      </p>
      <p>
        For the agreeableness trait, we found agreements with prior
work [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ] especially for the young adulthood group show: positive
correlations with Country, Folk, and Pop music. ese full
agreements seem to only hold for the young adulthood group. We found
less agreements with the adolescence and the middle adulthood
group: only Folk music showed to be positively correlated.
      </p>
      <p>
        e agreements we found with prior work [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ] on
neuroticism are divided across age groups. Whereas prior works showed
grouped correlations with Punk, Alternative, and Heavy Metal
music on neuroticism, our results show that these correlations do
not hold for all age groups. We show that Punk and Alternative
music is positively correlated with neuroticism for adolescence, but
only Alternative music is positively correlated with neuroticism
in the young adulthood group. Moreover, we show only a positive
correlation with Heavy Metal in the middle adolescence group.
6
      </p>
    </sec>
    <sec id="sec-10">
      <title>CONCLUSION &amp; IMPLICATIONS</title>
      <p>
        In this work we investigated whether there are dierences across
age groups in the relationship between personality traits and music
genre preferences. When not considering dierences across age
groups, we show that we found agreements with prior works [
        <xref ref-type="bibr" rid="ref20 ref23">20,
23</xref>
        ] on the relationship between personality and music genre
preferences. Whereas prior works analyzed their sample as a whole,
we show with our results that dierences exist in music genre
preferences depending on age groups. With our results we validate
the results of prior works, but show that there are cases where the
previously found correlations with music preferences are divided
over dierent age groups, whereas in other cases other (previously
unrevealed) correlations show up within age groups.
      </p>
      <p>Our work contributes to the personality-based work for
personalized systems. e dierences between age groups that we
identied in this work may have important implications for the
creation of personalized systems. e focus of the recommendations
may dier depending on the age groups a user falls in. For example,
the recommendations for adolescent extraverts could be focused
on R&amp;B music, whereas recommendations for extraverts in their
young adulthood could be more focused on Rap music.</p>
      <p>
        For our future work, we will extend our ndings by actually
trying to provide music recommendations to users and perform
a user-centric evaluation on the recommendations. For example,
including diversity in recommendations have shown to be an
important feature on satisfaction [
        <xref ref-type="bibr" rid="ref29">29</xref>
        ]. In addition, Ferwerda et al. [
        <xref ref-type="bibr" rid="ref6 ref7">6, 7</xref>
        ]
identied the prerequisites for diversication and found dierences
in diversity needs among personality traits. Our ndings could help
to inform the diversication in recommendations by incorporating
dierent needs across age groups. For example, those scoring high
on openness in their adolescence or young adulthood phases may
be given more diverse genres (correlations were found with eight
and ten dierent genres respectively), whereas the
recommendations for those in their middle adulthood can be narrowed down to
Blues and Folk.
      </p>
      <p>In this work, we also did not take into account possible cultural
dierences. Although having the music listening histories of users
from dierent countries, we disregarded country information in
order to keep a big enough sample. In future work we will address
possible cultural dierences.
7</p>
    </sec>
    <sec id="sec-11">
      <title>ACKNOWLEDGMENTS</title>
      <p>Supported by the Austrian Science Fund (FWF): P25655. We would
also like to thank Michal Kosinski and David Stillwell of the
myPersonality project for sharing the data with us.</p>
    </sec>
  </body>
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