=Paper= {{Paper |id=Vol-3731/paper29 |storemode=property |title=Unveiling Online Conspiracy Theorists: a Text-Based Approach and Characterization |pdfUrl=https://ceur-ws.org/Vol-3731/paper29.pdf |volume=Vol-3731 |authors=Alessandra Recordare,Guglielmo Cola,Tiziano Fagni,Maurizio Tesconi |dblpUrl=https://dblp.org/rec/conf/itasec/RecordareCFT24 }} ==Unveiling Online Conspiracy Theorists: a Text-Based Approach and Characterization== https://ceur-ws.org/Vol-3731/paper29.pdf
                         Unveiling Online Conspiracy Theorists:
                         a Text-Based Approach and Characterization
                         Alessandra Recordare1,* , Guglielmo Cola1 , Tiziano Fagni1 and Maurizio Tesconi1
                         1
                             Insitute of Informatics and Telematics (IIT), National Research Council (CNR), Via G. Moruzzi 1, 56124, Pisa, Italy


                                                                      Abstract
                                                                      In today’s digital landscape, the proliferation of conspiracy theories within the disinformation ecosystem of
                                                                      online platforms represents a growing concern. This paper delves into the complexities of this phenomenon. We
                                                                      conducted a comprehensive analysis of two distinct X (formerly known as Twitter) datasets: one comprising
                                                                      users with conspiracy theorizing patterns and another made of users lacking such tendencies and thus serving
                                                                      as a control group. The distinguishing factors between these two groups are explored across three dimensions:
                                                                      emotions, idioms, and linguistic features. Our findings reveal marked differences in the lexicon and language
                                                                      adopted by conspiracy theorists with respect to other users. We developed a machine learning classifier capable
                                                                      of identifying users who propagate conspiracy theories based on a rich set of 871 features. The results demon-
                                                                      strate high accuracy, with an average F1 score of 0.88. Moreover, this paper unveils the most discriminating
                                                                      characteristics that define conspiracy theory propagators.

                                                                      Keywords
                                                                      conspiracy theorist, disinformation, fake news, zero-shot learning, social media




                         1. Introduction
                         In the era of social networks, where the proliferation of misinformation and conspiracy theories has
                         become a growing concern, the need to identify users responsible for creating misleading content has
                         become imperative. In addressing disinformation, it is crucial to consider the role of social networks,
                         as they have been shown to act as significant amplifiers [1]. That is why examining the spread of
                         disinformation within social networks has become an area of growing research interest [2, 3, 4]. In
                         particular, in the aftermath of the COVID-19 pandemic, there has been an increased focus on the study
                         and understanding of conspiracy theories in general. This interest stems from the awareness of the
                         significant impact that these theories can have on public health, social cohesion, and the dissemination
                         of accurate information. In response to this challenge, this study aims to provide a contribution by
                         explaining an approach to identifying and profiling individuals who promote conspiracy theories on
                         social media [5].
                            This study builds upon prior research [6] where a technique was introduced to collect two datasets:
                         one consisting of apparent conspiracy theorists and the other of generic users, all sourced from X
                         (Twitter). Additionally, in that work a classification study was conducted to differentiate between
                         conspiracy and generic users, using a combination of psycholinguistic features and platform-specific
                         profile characteristics, including Following Count, Follower Count, Bio Sentences, Retweet Ratio, and
                         more. In our research, we seek to characterize conspiracy theorists solely based on their writing
                         style, moving away from dependencies on social network-related features. We explore three distinct
                         categories of features: emotions, idioms, and linguistic attributes. Moreover, we aim to identify the
                         specific features that prove to be crucial in making this distinction. Given the definition of “conspiracy
                         user” as someone who believes in conspiracy theories (conspiracy theorist), our research questions are:
                            RQ1 – Is it possible to identify a conspiracy user through text alone?
                            RQ2 – What are the features that differentiate a conspiracy user from a generic user?
                          ITASEC 2024: Italian Conference on CyberSecurity, April 08–11, 2024, Salerno, Italy
                         *
                           Corresponding author.
                          $ alessandra.recordare@iit.cnr.it (A. Recordare); guglielmo.cola@iit.cnr.it (G. Cola); tiziano.fagni@iit.cnr.it (T. Fagni);
                          maurizio.tesconi@iit.cnr.it (M. Tesconi)
                                                                   © 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).
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   Our investigation involved training various classifiers using three distinct classes of text-based
features, ensuring that our insights could be applied independently of the specific social networking
platform. The results show that the two groups of users exhibit divergent writing styles, underscoring
distinct attitudes. Moreover, we identified which types of features are most effective in revealing the
tendency to adhere to conspiracy theories.
   The paper is organized as follows. In the following Section we briefly present some of the most
relevant studies in the field of fake news and conspiracy theories detection. In Section 3, we describe
the X dataset and the preprocessing steps required for our analysis. Next, in Section 4.1, we show and
describe the adopted features. Section 5 shows the analysis we performed on the dataset. Finally, in
Section 6, we summarize our findings and suggest avenues for future research.


2. Related work
Social media have greatly facilitated the dissemination of unverified information and misleading
content [1, 3, 7]. There has been extensive research on fake news detection to enable the analysis of fake
news spreaders. A relevant example is the study in [8], which revealed that there are characteristics
(most dependent on social media) that differ between users who share fake news and those who share
real news. Giachanou et al. in [9] proposed a system that exploits a set of psycholinguistic characteristics
and personality traits inferred by users to discriminate between potential spreaders of fake news and
fact-checkers.
   Recent years have seen an increasing focus on the study of conspiracy theories among fake news
and disinformation, especially in response to global events such as the COVID-19 pandemic [1, 10].
Alternative explanations for historical or ongoing events, which claim that individuals or groups
with malevolent intentions are involved in occult conspiracies, have infiltrated online communication,
popular culture, political discourse, and various other areas [11]. Researchers are studying how these
theories spread across different social platforms, analyzing the mechanisms that lead to their adoption
by individuals and trying to identify and characterize conspiracy users in different ways [12, 13, 14, 15,
16, 17]. While conspiracy theories have recently been associated with vaccines, their scope extends to
several other realms. For example, Marcellino et al. [5] collected and analyzed online discussions related
to four specific conspiracy theories. Klein et al. [18] examined users posting a variety of conspiracy
theories on Reddit, analyzing differences in the language used by conspiracy theorists compared to
other users. The work of Fong et al. [19] analyzed conspiracy theories posted by influencer users on
Twitter. Bessi et al. [20] examined the differences between Facebook users who adhere to conspiracy
theories and those who do not, characterizing the personalities of the two groups.
   Many of these studies have suggested the possibility of distinguishing the two user groups, yet they
lack detailed insights into the extent of this differentiation. Our aim is therefore to distinguish between
“conspiracy users” and other users on social media and to give them a characterization. Our work
differs from those mentioned above in that we determine whether a user is a conspiracy user by using
only the text of posted tweets, independently of other dynamics of the social networking platform. In
this context, a relevant study is presented in [21], where a classifier for conspiracy users is described.
However, unlike their approach, we do not seek a distinction between users who support conspiracy
theories and users who refute them, but instead compare apparent conspiracy theorists with generic
users discussing the same topics. Additionally, while their focus was on a narrow range of conspiracies,
our study considers a broader set of conspiracy theories.


3. Dataset description
In this section, we present a detailed account of the initial dataset sourced from [6] as well as the specific
preprocessing steps that were executed to adapt the dataset to the objectives of our research.
   This initial dataset includes two distinct sets, each consisting of 7,394 X users. The first set, the
“conspiracy group”, comprises users identified as conspiracy theorists. The second set, the “control
group”, includes users not exhibiting apparent conspiracy theory patterns. Conspiracy users were
identified by analyzing likes and follows of well-known conspiracy pages or accounts. Instead, the
control group consists of users who neither explicitly liked nor followed such content, but still engaged
in discussions on the same controversial topics as the conspiracy group and were created around the
same time. For each user, the last 3,200 tweets were collected, as of June 13, 2022. The dataset is publicly
available1 .
   To ensure the dataset’s relevance and reliability for our research objectives, a series of preprocessing
steps were undertaken:

       • Removal of Retweets: To enhance the dataset’s suitability for profiling users, we chose to
         exclude retweets. Retweets, being reposts of other’s content, introduce redundancy. By excluding
         them, we ensured that the dataset primarily consists of original content, aligning with our goal
         of characterizing users based on their own tweets.
       • Language Filter: Our analysis focused exclusively on tweets composed in the English language.
         Implementing this filter was crucial for the subsequent phases of our research and ensured
         linguistic coherence in our dataset.
       • User Tweet Count Threshold: To ensure the inclusion of users who have a sufficient presence
         on X, we implemented a per-user tweet count threshold. Specifically, we excluded users with
         fewer than 10 tweets within the data collection period. This helped improve the accuracy and
         reliability of the user profiling we aimed to achieve.
       • Selection of Latest 100 Tweets per User: Obtaining a large number of tweets from a single
         user is often challenging in practice. To address this, we focused our analysis on the most recent
         100 tweets for each user. This approach reflects more closely real-world scenarios, where several
         users do not have a high volume of tweet activity.

   These preprocessing steps transformed the dataset into a more suitable form for our research ob-
jectives. As a result, our dataset contained 547,724 tweets from conspiracy users and 592,927 tweets
from the control group, posted by a total of 14,568 users. We then balanced the dataset using a Random
Undersampling technique, achieving a total of 7,210 conspiracy users and 7,210 control group users.


4. Method
The objective of our study is to characterize conspiracy users through a series of steps: identifying
suitable features that are dependent solely on the text of the tweet and are not influenced by the
platform, conducting a classification task to distinguish between the two groups, and analyzing the
most significant features using feature importance metrics. This analysis aims to discern the stylistic
differences between the two user groups while ensuring the exclusion of platform-related factors.
   In this section we present the features used to characterize users based on their tweets as well as the
classification methods employed to discriminate between conspiracy theorists and other users.

4.1. Features
We opted to employ three distinct feature groups, all centered around the text content of each individual
tweet:

      1. Emotions: We included this feature group to partially implement a sentiment analysis on the
         dataset. The emotions we have chosen are Anger, Fear, Joy, Sadness, Disgust, Surprise, Anticipation,
         and Trust. These emotions align with Robert Plutchik’s model of basic emotions, which is widely
         recognized in the field of psychology [22]. To assess the emotional content of each tweet, we em-
         ployed zero-shot learning techniques. Specifically, we used the facebook/bart-large-mnli

1
    https://zenodo.org/records/8239530
         model available on Hugging Face 2 as a sentiment classifier. This pre-trained model provides
         a score on a scale from 0 to 1, where a score of 0 indicates no agreement between the emotion
         and the tweet, while values approaching 1 indicate a strong agreement between them. The
         facebook/bart-large-mnli model is well known for its accuracy in discerning emotional content in
         text data [23]. This agreement calculated between the emotion and the tweet will be the feature
         used for our work.
      2. Idioms of conspiracy theorists: 44 sentences were generated by chatGPT-3.5 using the follow-
         ing prompt:
          What are the typical idioms of a conspiracy theorist?
          Some sayings that come to mind are:
          > - think/reason/. . . with your head
          > - they won’t tell you any of this
          > - they don’t tell us
          > - nobody talks about it
          > - wake up!
          > - strong powers
          > - they make fun of us
          > - that’s enough
          Do you know any other interesting ones?

         These idioms are detailed in Table 1 and they aim to represent the typical language used by
         conspiracy theorists on social media. The agreement between tweets and idioms was assessed
         using the zero-shot learning capability of the facebook/bart-large-mnli model, similarly to the
         method used for emotions. The agreement score, ranging from 0 to 1, was utilized as a feature for
         subsequent analyses.
      3. Linguistic features: We have identified five sets of linguistic features for a total of 72: lexical (e.g.,
         num_words),syntactical (e.g. num_sentences), semantic (e.g., num_named_entities), structural
         (e.g., avg_sentence_length), and subject-specific features (e.g., flesch_reading_ease). The full list is
         reported in Table 2.

   Table 3 shows the number of features per each group.
   After selecting these features to characterize users, we decided to aggregate tweets by individual users.
This transformation resulted in a dataset where each row represents an individual user, rather than
an individual tweet. To achieve this, we computed 7 descriptive statistics, namely the mean, median,
standard deviation, minimum, maximum, lower quartile, and uppr quartile for the values associated with
the tweets of the same user. For instance, when considering the feature ’num_sentences’, the statistics
were computed by aggregating values of ’num_sentences’ across all tweets authored by an individual
user. As a result, each feature was expanded into 7 distinct statistical measures. This aggregation
process provided us with a more holistic perspective on the characteristics of each user, facilitating
the summarization of tweet-level attributes into user-level attributes. After this step, our final dataset
comprised 14,420 rows (users) and 868 features.

4.2. Classification
The dataset was split into training (85%) and test (15%) sets. Classification was conducted using either the
three groups of features individually or a combined set incorporating all of them. We evaluated a variety
of classifiers, including Logistic Regression, K-Nearest Neighbours (K-NN), Naive Bayes, Support Vector
Machine (SVM), Decision Trees, Random Forest, Gradient Boosting, such as XGBoost and LightGBM,
Quadratic Discriminant Analysis (QDA), Multilayer Perceptron (MLP), Ridge Classifier, and Linear
Discriminant Analysis (LDA). For each classification algorithm, stratified k-fold cross-validation was
utilized on the training set to fine-tune the parameters.


2
    https://huggingface.co/facebook/bart-large-mnli
                                                   Idioms
 Behind closed doors                                   They want to keep us in the dark
 Don’t let them catch you                              They will not tell you anything about this
 Don’t let the cat out of the bag                      They’re cooking up something nefarious
 Follow the money                                      They’re out to get us
 It’s a cover-up                                       They’re planning something behind our backs
 It’s a deep state conspiracy                          They’re plotting something sinister
 It’s all part of the plan                             They’re trying to cover up their tracks
 Nobody talks about it                                 They’re trying to distract us from the real issue
 Now enough!                                           They’re trying to divide us
 Pulling the strings                                   They’re trying to silence us
 Pulling the wool over our eyes                        Thinking with your head
 Question everything                                   Trust no one
 Strong powers                                         Wake up!
 The conspiracy runs deep                              Watch your back
 The enemy is among us                                 We have to be prepared
 The truth is hidden                                   We have to stay one step ahead of them
 The truth is out there                                We have to stick together
 The truth is suppressed                               We have to watch our backs
 The truth will set us free                            We need to be careful who we trust
 They don’t tell us                                    We need to dig deeper and uncover the truth
 They don’t want us to know the truth                  We need to stay one step ahead of them
 They make fun of us                                   We need to uncover their secrets
Table 1
List of idioms used among conspiracy theorists


5. Result and Discussion
We first report the results achieved in recognizing conspiracy users from the text contained in their
tweets (RQ1). Subsequently, we explore the feature importance within the three groups defined in
Section 4.1, in order to unveil the key features that characterize conspiracy theorists (RQ2).

5.1. Conspiracy users classification
In the classification task, as mentioned above, we evaluated various classifiers using a single group of
features (emotions, idioms, or linguistic) or all of them combined. For emotions, the best performance
was achieved with Logistic Regression. For idioms, the best results were obtained through Logistic
Regression, Ridge Classifier, and Linear Discriminant Analysis (LDA). On the other hand, for linguistic
features and for the combined features, the best performances were achieved using the Light Gradient
Boosting Machine (LGBM) algorithm. Classification results are shown in Table 4.

5.2. Feature importance
From these results, it is apparent that the feature group which excels at distinguishing between con-
spiracy users and control group is the set of linguistic features. Figure 1 shows the 20 most important
features for discriminating between control group users (on the left) and conspiracy users (on the
right). Blue points represent low feature values, while red points indicate high values. The SHAP
value (the distance from the central vertical axis) indicates the importance of that feature for clas-
sification. The analysis of the 20 most crucial features for classification shows that the top 10, in
terms of importance, originate from the linguistic feature group, with the remaining 10 linked to
idioms. Notably, none of the top 20 features are related to emotions, suggesting that emotional features
have relatively limited discriminatory power between the two user groups. The most discrimina-
tive feature is mean(num_coord_clauses), showing lower values for conspiracy users, followed by
 Class               Features                                                                Description
 Lexical             num_words; num_unique_words; num_chars; num_unique_chars;               Word-level characteristics
                     avg_word_length; num_stop_words; num_punct; num_digits;                 and properties of text.
                     num_upper_case_words; num_lower_case_words; num_title_case_words;       They include various mea-
                     num_proper_nouns; num_nouns; num_verbs; num_adjectives;                 surements related to the
                     num_adverbs; num_pronouns; num_named_entities; num_noun_chunks;         vocabulary and composition
                     num_exclamation_marks; num_question_marks; num_spaces                   of words within a given text.
 Syntactical         nominal_forms; voc_rich; num_sentences; avg_num_words_per_sentence;     Grammatical structure and
                     num_noun_phrases; num_verb_phrases; num_adj_phrases;                    syntax of sentences within a
                     num_adv_phrases; num_prep_phrases; num_coord_conj; num_subord_conj;     text. They capture the orga-
                     num_coord_clauses; num_subord_clauses; punctuation_freq;                nization and relationships of
                     num_capitalized_sentences; num_caps_word_freq; num_participial;         words and phrases in terms
                     num_present_tense; num_complementation; num_relative_clause             of syntactic rules.
 Semantic            num_personal_pronouns; num_impersonal_pronouns;                         Meaning and interpretation
                     num_possessive_pronouns; num_reflexive_pronouns;                        of words and phrases within
                     num_reciprocal_pronouns; num_quantifiers; num_determiners;              a text. They capture the un-
                     num_prepositions; num_aux_verbs; num_modal_verbs; num_negations;        derlying semantics and con-
                     num_synonym; num_antonymy; 1st_person_pronouns;                         text of language.
                     2nd_person_pronouns; num_passive_verbs
 Structural          avg_sentence_length; avg_word_length; avg_noun_phrases_per_sentence;    Overall organization and
                     avg_verbs_per_sentence; proper_noun_ratio                               composition of the text
                                                                                             at a higher level, such as
                                                                                             sentence and paragraph
                                                                                             structure.    They provide
                                                                                             insights into the textual
                                                                                             coherence and complexity.
 Subject-specific    flesch_reading_ease; smog_index; flesch_kincaid_grade;                  Specialized indicators rele-
                     coleman_liau_index; automated_readability_index;                        vant to specific domains or
                     dale_chall_readability_score; difficult_words; linsear_write_formula;   topics within the text.
                     gunning_fog

Table 2
List of linguistic features divided by class

           Emotions      Idioms                                   Linguistic Features
                                       Lexical     Syntactical      Semantic Structural       Subject-specific
                8            44          22            20              16          5                 9
Table 3
Number of features used per group


mean(num_reflexive_pronouons) and mean(num_possessive_pronouons), both showing higher values for
conspiracy users.
   Figure 2 depicts the variation of the F1 score as a function of the number of features employed in the
classification, arranged according to their order of importance. We can see that by utilizing the first
30 features, the maximum F1 score is achieved, and notably, even with just the first 14 features, an F1
score of 0.85 is attained.
   In the following subsections, we provide a detailed analysis on the relevance of each group of features
in recognizing conspiracy users, directly addressing our second research question (RQ2).

5.3. Emotions
We conducted an in-depth analysis of emotion-based feature importance in the LGBM classifier and
observed that the most prominent distinguishing emotion between the two user groups is “disgust”,
followed by “joy”, “sadness”, and “anticipation”. Figure 3 shows the 20 most important emotional
features for discriminating between control group users and conspiracy users.
  Classifier                Emotion           Idioms             Linguistic features      All features
                      Prec. Recall F1 Prec. Recall           F1 Prec. Recall F1 Prec. Recall F1
  Logistic regression 0.74    0.81  0.77 0.80   0.85       0.82 0.79    0.83     0.81 0.83     0.85   0.84
  K-NN                 0.70   0.73  0.72 0.77   0.69        0.73 0.70   0.76     0.73 0.76     0.75   0.75
  Naive Bayes          0.61   0.95  0.74 0.65   0.92        0.76 0.54   0.98     0.69 0.60     0.96   0.73
  SVM                  0.75   0.78  0.76 0.78   0.69        0.73 0.76   0.78     0.77 0.82     0.85   0.83
  MLP                  0.73   0.74  0.73 0.81   0.80        0.81 0.80   0.78     0.79 0.85     0.84   0.85
  Ridge Classifier    0.73    0.82  0.77 0.80   0.85       0.82 0.78    0.83     0.80 0.81     0.87   0.84
  LDA                 0.73    0.82  0.77 0.80   0.85       0.82 0.78    0.83     0.80 0.81     0.87   0.84
  DT                   0.68   0.67  0.67 0.70   0.70        0.70 0.70   0.70     0.70 0.72     0.70   0.71
  RF                   0.73   0.79  0.76 0.76   0.84        0.79 0.77   0.77     0.77 0.78     0.84   0.81
  XGBoost              0.73   0.77  0.75 0.78   0.85        0.81 0.83   0.87     0.85 0.85     0.88   0.86
  LightGBM             0.74   0.79  0.76 0.78   0.85        0.81 0.84   0.87    0.86 0.86      0.89   0.87
  Mean                0.703 0.802 0.752 0.756 0.818        0.780 0.731 0.751 0.716 0.766 0.779 0.752
Table 4
Precision, Recall and F1 score on test sets




Figure 1: SHAP values for the 20 most important features considering all features


   For the “disgust” emotion, the average, median, standard deviation, and 75th percentile values were
significantly higher for conspiracy users. In the control group, the mean and seventy-fifth percentile
of the “joy” emotion exhibited higher values. As for the “sadness” emotion, conspiracy users showed
higher mean and 75th percentile values compared to the control group. Interestingly, for the “anger”
emotion, both the mean and median were higher in the control group.
                                                F1 Score's variation based on the number of features used


                                 0.85




                                 0.80




                      F1 Score   0.75




                                 0.70




                                        0   5     10          15          20            25        30        35   40
                                                                   Number of features


Figure 2: F1 score based on the number of features used for classification (ordered by feature importance)
considering all features




Figure 3: SHAP values for the 20 most important features in the emotions set


5.4. Idioms of conspiracy theorists
Figure 4 is a heatmap showing the average values of several descriptive statistics for the majority of
idioms in our analysis, divided by user group (control group and conspiracy users). The average of each
descriptive statistic was computed among all the users in a group. Cells with higher values tend towards
yellow, whereas lower values are represented by violet blue cells. We excluded the least discriminating
idioms and statistics for better readability.
   Most of the idioms identified by ChatGPT tend to align more closely, on average, with tweets from
conspiracy theorists, except for We have to stick together, Strong powers, It’s all part of the plan, The
Figure 4: Descriptive statistics relative to the analyzed idioms, for control group users and conspiracy users


truth will set us free, and Follow the money, which align more with tweets from the control group. Some
idioms exhibit a strong agreement with both user groups, like We have to be prepared, while others show
little agreement for either group, such as Trust no one, They’re plotting something nefarious, and The
enemy is among us. The average standard deviations are consistently higher for conspiracy theorists,
suggesting that this group has more diverse data among themselves. There are substantial differences in
the averages of the 75th percentiles, for example, in phrases like Pulling the wool over our eyes, Question
everything, and The conspiracy runs deep, where quite higher values are noted for conspiracy users. This
indicates that agreement values for these idioms tend to be higher for this class of users.

5.5. Linguistic features
As previously mentioned, linguistic features have proven to be the most effective in classifying con-
spiracy and control group users. To further explore this, we divided these features into five groups:
lexical, syntactical, semantic, structural, and subject-specific features. Our goal was to ascertain which
of these groups contributed most significantly to the differentiation between the two user classes.
Regarding their utility for classification, we found that semantic features ranked the highest, followed
by syntactical, lexical, subject-specific, and, lastly, structural features. This observation is corroborated
by Figure 5, which illustrates that the top 20 features contributing to classification predominantly belong
to the semantic, syntactical, or lexical categories.
   Among the most significant semantic features are the average count of reflexive pronouns, the
average count of possessive pronouns (in both cases, the number of pronouns mentioned is higher for
conspiracy users), and the average count of named entities (conspiracy users tend to mention fewer
entities). As for syntactical features, the mean and standard deviation of the number of coordinating
clauses, along with the standard deviation of the number of subordinate clauses, were identified as the
most important. Both of these features exhibited higher values among conspiracy theorists. Among
the prominent lexical features, the mean count of digits (higher for conspiracy users) and the standard
deviation of title case word count (also higher for conspiracy users) were found to be the most influential.
Other noteworthy features include the higher count of question marks among conspiracy users, as
well as vocabulary richness, indicating a more sophisticated word choice in their tweets. Furthermore,
Figure 5: SHAP values for the 20 most important features in the linguistic set


all readability indices suggest a greater level of reading difficulty (and therefore lower readability) in
tweets of conspiracy users. This is likely attributed to the usage of acronyms or hashtags typical of the
movement they support.


6. Conclusions and future work
In this study, we introduced a method for profiling users who endorse conspiracy theories, focusing
specifically on characterizing their writing style. This characterization was achieved by analyzing
textual content of tweets, intentionally excluding platform-dependent metrics such as likes, retweets,
and comments.
   We selected a dataset consisting of 14,420 users, evenly split between two categories: 7,210 conspiracy
users and 7,210 control group users, who did not exhibit explicit conspiracy theory behavior patterns.
For each user, we analyzed between 10 to 100 of their most recent tweets, calculating scores based solely
on textual content. These scores were subsequently aggregated for each user, using statistical measures
like mean and median to capture the essence of each user’s textual patterns. We also implemented and
tested classification algorithms, with the Light Gradient Boosting Machine classifier yielding the most
promising results. This classifier enabled us to effectively differentiate between conspiracy and control
users, achieving an F1 score of 0.87.
   Responding to RQ1, this research has shown that users can be categorized based solely on the
characteristics of their writing style. Furthermore, in response to RQ2, this study identified specific
linguistic traits that can be considered characteristic of conspiracy theorists, thus shedding light on
the distinct markers of this group within the digital landscape. We found that the features that best
characterize conspiracy users from the control group are linguistic features, in particular the number of
coordinate clauses, the number of possessive and reflexive pronouns. Our work shows that conspiracy
theorists use fewer coordinate clauses than the control group but more reflexive and possessive pronouns,
use more digits, name fewer entities, use a richer vocabulary and have worse readability. Regarding
sentiment analysis, the tweets from conspiracy users show a higher agreement with disgust and sadness,
while the tweets of the control group are more akin to joy and anger. Considering the set of conspiracy
idioms generated via chat-GPT, it turns out that most of them have a higher agreement with conspiracy
users.
   In future work, we plan to extend our classifier’s application to other platforms like Telegram. This
will help assess the model’s generalizability and robustness across diverse social media. Furthermore,
we plan to improve the accuracy of our model by incorporating a wider range of text-only features,
enhancing our understanding of user behavior and the overall ability of recognizing conspiracy theorists.
Additionally, we are interested in exploring different time windows to capture evolving trends and
emerging patterns in the propagation of conspiracy theories. Lastly, an interesting avenue for future
research is examining the implications of our findings on disinformation mitigation strategies. This
could lead to more effective methods to counter the spread of disinformation and promote digital
literacy.


Acknowledgments
We acknowledge the support provided by project SoBigData.it, which receives funding from European
Union – NextGenerationEU – National Recovery and Resilience Plan (Piano Nazionale di Ripresa e
Resilienza, PNRR) – Project: "SoBigData.it – Strengthening the Italian RI for Social Mining and Big Data
Analytics" – Prot. IR0000013 – Avviso n. 3264 del 28/12/2021. This work is also supported by project
SERICS (PE00000014) under the NRRP MUR program funded by the EU – NGEU.


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