Background: In the REASON4HEALTH project, we explored the structure, prevalence, and psychological factors predicting intentional non-adherence to official medical recommendations (iNAR) and the use of traditional, complementary, and alternative medicine (TCAM) in Serbia. Methods: Focus groups with clinicians and TCAM practitioners and a literature review informed the development of instruments assessing iNAR and TCAM use. We tested these instruments in an online sample of 583 adult Serbian citizens (M_age = 39.01, SD_age = 12.10) and collected data on iNAR, TCAM, and relevant psychological factors in a nationally representative sample (N = 1003, M_age = 39.01, SD_age = 16.67). Results: Intentional non-adherence behaviors (avoiding medical check-ups, self-medication, and self-initiated changes in therapy) formed a single factor. TCAM use formed an overarching factor with four domains: natural product-based practices, alternative medical systems, “new age” practices, and customs/rituals. The nationally representative sample revealed a lifetime prevalence of iNAR at 91.3%. Notably, 47% had taken antibiotics without a prescription, and 29% changed therapy without consulting a doctor; 97% used natural-product based practices, 75% engaged in customs/ rituals, 49% used alternative medical systems, and 35% participated in “new age” practices. Physicians highlighted a lack of health education, insufficient time with patients, and simplicity of TCAM as factors influencing these behaviors, while TCAM practitioners cited a holistic approach and a dedicated relationship with patients. Negative experiences with the health system predicted iNAR (b = .19 to .25, p < .001). Irrational beliefs, such as magical beliefs about health (b = .13 to .25, p < .05), superstitions (b = .19, p < .01), and beliefs in extrasensory perception (b = .11, p < .01) predicted TCAM use. Conclusion: Our studies highlight the widespread prevalence of iNAR and TCAM and underscore the need for interventions targeting unfounded beliefs and improving patients’ experiences with the health system.

Irrational beliefs are the main theoretical construct of rational-emotive and behavioral therapy (REBT), referring to beliefs that are rigid, extreme, inconsistent with reality, illogical, and maladaptive for the person endorsing them. Though endorsing irrational beliefs leads to various maladaptive behaviors (e.g. procrastination or avoidance), there
is scarce data on their role in unhealthy behaviors. Intentional nonadherence is a new construct (Purić et al., 2023) that refers to a general tendency to not adhere to official medical recommendations, among the general population. It comprises self-medicating, avoiding medical appointments, and rejecting or changing the prescribed therapy. This
behavior can have serious health consequences for the individual and the society – we know that antimicrobial resistance is one of the top 10 global public health threats according to WHO. In a wider project on health behaviors (REASON4HEALTH), we found that intentional nonadherence is widespread. In this paper, we investigated the role of
irrational beliefs broadly defined, in predicting intentional non-adherence. Therefore, besides REBT irrational beliefs, we included conspiracist beliefs, magical health beliefs, superstition, and extrasensory perception. These beliefs refer to socially developed and shared ideas that lack an evidence base or contradict established scientific principles. We
report data from three samples (a community sample from Bosnia and Herzegovina, N1= 530; a quota sample from Serbia N2 = 265; and a representative sample from Serbia, N3 = 1003). REBT irrational beliefs were correlated with intentional nonadherence in all three samples (from .08, p < .05 to .22, p < .001). We conducted hierarchical regressions to investigate whether irrational beliefs predict intentional nonadherence above sociodemographic variables and self-perceived health status entered in the first block and experiences with and/or trust in the medical system entered in the second block. REBT-derived irrational beliefs were entered into a block alongside other irrational beliefs. The latter refers to socially developed and shared ideas that lack an evidence base or contradict established scientific principles. Due to the large scale of the project, REBT irrational beliefs were measured with a very short 6-item scale
(Owings et al, 2013). In samples 1 and 2 the irrational beliefs block made a significant incremental change, and specifically, REBT-derived irrational beliefs were a significant predictor of intentional nonadherent behavior (βs were .12, p <.01 in sample 1 and .17, p <.01 in sample 2). Our data offers preliminary evidence for the role of REBT irrational beliefs in nonadherent behavior, suggesting the possibility of preventive medical programs. Future studies should include the long version of the measure of irrational beliefs, and seek to refine the evidence for specific irrational beliefs (e.g. frustration intolerance).

Background. Refusing or postponing vaccination is an individual decision that can have serious consequences for personal and public health. These behaviors can be rooted in irrational beliefs that contradict scientific principles or cognitive biases (errors in judgment and decision-making), or result from mistrust in the healthcare system. We
tested the predictiveness of these factors to two categories of vaccination behaviors: self-vaccinating against COVID-19 and postponing/refusing to vaccinate one’s child according to the official immunization schedule.
Methods. In a community sample of Serbian adults (N = 582; 249 reported having children), we measured irrational beliefs (conspiracy beliefs, magical health beliefs, superstitiousness), cognitive biases (illusory correlation, omission bias, naturalness bias), trust in the healthcare system and professionals, health, socioeconomic status,
age, gender, and education.
Findings. While 22% of the sample was not COVID-19 vaccinated, 2% of parents refused, and 15% postponed vaccinating their children. Expectedly, COVID-19 vaccination was predicted by older age (β = .19), poorer health status (β = -.10), lower conspiracy (β = -.14) and magical health beliefs (β = -.20), lower naturalness bias (β = -.18), and higher trust in the healthcare system &#40;β = .15&#41; and professionals (β = .14) (all ps <. 01). However, postponing/refusing vaccinating children was not predicted by an irrational mindset or system mistrust. Younger participants rejected vaccinating their children more often (β = -.25, p < .001).
Discussion. Results suggest that vaccination behavior is heterogeneous and has different roots, implying different intervention strategies are needed to address the different types of vaccine hesitancy.

Non-adherence to medical recommendations is a widespread public health challenge, attributed to socio-economic, healthcare system, condition, therapy, and patient-related barriers (WHO, 2003). The novel iNAR-12 instrument (Puric et al., 2023) assesses intentional non-adherence to medical recommendations which is a result of a deliberate process, including behaviors like treatment avoidance or modification and self-medication. This study investigated the prevalence of intentional non-adherence behaviors in Serbia and its psychological roots. This cross-sectional survey was conducted on a probability sample of 1003 participants, nationally representative
of Serbia. The battery of instruments included iNAR-12 and scales assessing personality (HEXACO and Disintegration), health status, socio-demographics, healthcare-related beliefs, and experiences, along with thinking styles, and the “irrational mindset” set of questionnaires, which included magical health beliefs, health-related conspiracies and selected cognitive biases. As much as 91.3% of the Serbian adult population reported at
least one instance of intentional non-adherence in their lifetime, with the most frequent behaviors being ignoring symptoms that required a visit to a doctor (78%) and taking antibiotics when not prescribed by a doctor (47%). While there were significant correlations (ps<.01) between iNAR and personality traits (H, X, A, D), and the
irrational mindset (medical conspiracies, commitment bias, illusory correlations), the hierarchical linear regression demonstrated that negative experiences with the healthcare system were its strongest predictor. The results suggest that intentional non-adherence is a widespread phenomenon. Future health interventions should address modifiable factors such as enhancing healthcare experiences and tailoring communication to individuals at higher risk of intentional non-adherence.

Irrational beliefs encompass a broad set of beliefs that lack empirical evidence and contradict scientific principles. This research investigates whether and to what extent they can be shaped by cognitive biases. Across three studies, illusory correlation, naturalness bias, and omission bias consistently predicted conspiracist beliefs, magical health beliefs, and superstitions over and above a comprehensive set of socio-political variables. Our findings indicate the nuanced nature of these relationships, as the predictive power of individual cognitive biases was partially contingent on the specific irrational belief.

World Health Organization recognizes non-adherence to medical recommendations as a global health-threat. Some non-adhering behaviors are typical examples of the “tragedy of the commons“, e.g. while taking antibiotics without prescription seems a straightforward strategy to relieve the symptoms, it has a cumulative effect on global antimicrobial resistance. This makes studying the roots of these behaviors a legitimate psychological issue. Various factors can affect non-adherence: a) socio-demographic b) health-related c) personal-psychological, such as personality traits, and d) system-related, such as trust in the healthcare system and experiences of discrimination within it. They are, however, rarely compared in a single design, which could lead to overestimating the effects of a certain group (typically psychological factors in psychological studies).

Across three studies in Serbia (total N = 1725) we tested the explanatory power of personality traits and systemic factors for intentional non-adherence (iNAR), such as self-medication, modification or discontinuation of prescribed therapy or skipping check-ups and follow-ups, while controlling for age, gender, SES, and health status. We first examined how HEXACO personality traits predict iNAR (Study 1). We then tested the power of distrust in the healthcare system and experiences of discrimination within it to predict iNAR (Study 2). Finally, on a probabilistic nationally representative sample, we introduced both groups of predictors (Study 3). Results suggest that, while there is a modest contribution of personality traits, thatsystemic factors are essential for non-adherence. This calls for systemic changes, rather than (or at least complementary to) individual-related interventions, in order to reduce non-adhering health behaviors.

The internet offers a myriad of scientifically unfounded health advice. That way you can, for example, learn that you should purify your body by drinking dubious concoctions or taking untested supplements. These recommendations often rely on magical health beliefs (e.g. that the toxins accumulate in the body or that food roots in it). There is conflicting evidence about ideological roots of such beliefs: whilst they are sometimes viewed as a part of a typically left-liberal, New age worldview, they are also a form of epistemically suspect beliefs, more present in conservatives. Across three samples from Serbia (two community, and one probability representative sample), we explored the sociodemographic and ideological profile of magical health beliefs endorsers. In Study 1 (N=224), age, gender, education and socioeconomic status did not predict magical health beliefs, while right-wing and more religious people were more likely to endorse them. In Study 2 (N=500), we added the economical axis to better distinguish the ideological profile of endorsers. We found that women, older participants, those less educated and with poorer socioeconomic status were more likely to hold magical health beliefs. Moreover, political orientation and religion contributed over and above sociodemographics, with only social conservatism contributing significantly. In Study 3 (N=1003), we replicated the finding that women and older participants are more susceptible, and once again religion and social right-wing ideology contributed additional variance. These ideological profiles might help in tailoring public health messages aiming to reduce magical health beliefs and their consequences.

Medical practices that fall outside of conventional medicine are usually referred to as traditional, complementary, and alternative medicine (TCAM). Although TCAM may offer certain health benefits, its use may have adverse effects, or be contraindicated with certain conditions or prescribed therapy. This, and the fact that TCAM is increasingly being used despite a lack of evidence of its efficacy, calls for further investigation to map who finds these practices especially appealing. A\s research suggests that specific irrational beliefs could be relevant for susceptibility to TCAM use, we opted to include a broader set of irrational beliefs in a single design and test their validity in explaining TCAM use. We did that across four samples: a community sample from Serbia (N1=575); a community sample from Bosnia and Herzegovina (N2=561); a quota sample from Serbia (N3=224); and a representative sample from Serbia (N4=1003). TCAM use was measured using a 22-item checklist that included practices based on natural products (e.g., herbal teas, balms, honeybee products), alternative medical systems (e.g., acupuncture, homeopathy), New Age medicine (e.g., yoga, meditation, mindfulness) and rituals/customs (e.g., wearing amulets, drinking water from healing springs). For irrational beliefs, we assessed superstition, general conspiratorial, and magical health beliefs in all samples. We added medical conspiratorial beliefs in Samples 2-4, and extrasensory perception beliefs for sample 4. The results of the regression analyses demonstrated that irrational beliefs explain between 8.7% (Sample 4) and 23.3% (Sample 3) of TCAM use across the four samples. While magical health beliefs and superstition were the best predictors of TCAM use in Studies 1-3 (their predictiveness varied between .17 and .28), in Study 4 extrasensory perception beliefs and medical conspiratorial beliefs had the highest predictive power (predictiveness .26 and .07 respectively). Although specific predictors differed to some extent between the samples, the overall pattern of results was consistent and emphasized the important role of irrational beliefs in TCAM use.

Keywords: irrational beliefs, traditional, complementary and alternative medicine (TCAM) use, health behaviors

Irrational beliefs, characterized by a lack of empirical evidence or contradiction with scientific principles, encompass a broad spectrum of beliefs, typically classified into conspiratorial, pseudoscientific, and paranormal domains. Previous research has shown substantial interrelations among these domains. In this research, across four studies, we explore the latent structure of irrational beliefs and investigate whether they can be ascribed to one underlying factor. We collected data from diverse samples (N1 = 506, N2 = 506, N3 = 220, N4 = 921) with each study including at least one measure representing each of the three presumed domains: paranormal (Superstitiousness and Extrasensory perception beliefs), pseudoscientific (Magical health beliefs and Attitudes towards traditional, complementary and alternative medicine), and conspiracist (General conspiracist beliefs and Medical conspiracist beliefs). Despite using brief versions of all instruments, their internal consistency was higher than .75, while correlations among irrational beliefs were consistently positive and ranged from r = .14 (between General conspiracist beliefs and Superstitiousness in Study 3) to r = .70 (between Medical conspiracist beliefs and Magical health beliefs in Study 1). We used exploratory factor analysis (EFA) with maximum likelihood extraction to test the latent structure of irrational beliefs. By employing parallel analysis, scree plot analysis, and Kaiser’s criterion to determine the optimal number of factors, we retained a single latent factor in each study, whose explained variance ranged from  39% (Study 4) to 52% (Study 1). While each of the measures had significant loadings on this factor, conspiracist and pseudoscientific beliefs consistently exhibited higher loadings ranging from .57 to .94 than paranormal beliefs, which ranged from .37 to .55. These results indicate that various irrational beliefs, despite their distinct content, are best understood as manifestations of a general tendency to hold beliefs that lack a rational basis or empirical support.

Keywords: irrational beliefs, conspiratorial beliefs, pseudoscientific beliefs, paranormal beliefs, exploratory factor analysis

Projekat REASON4HEALTH je pomoću kvalitativnih i kvantitativnih metoda istražio strukturu, prevalencu i psihološke faktore koji mogu predvideti dve vrste upitnih zdravstvenih ponašanja: namerno nepridržavanje zvaničnih preporuka lekara i korišćenje tradicionalne, komplementarne i alternativne medicine (TKAM) u Srbiji. Na uzorku od N = 583 odraslih građana Srbije (74.4% женског пола, Mузраст = 39.01, SDузраст = 12.10)  pokazalo se da ponašanja namernog nepridržavanja (izbegavanje lekarskih pregleda, samomedikacija i samoinicijativno menjanje terapije) čini jedan faktor.  Korišćenje TKAM objašnjava jedan krovni faktor, i četiri domena koja su u skladu i sa postojećim taksonomijama: korišćenje suplemenata i biljnih preparata, alternativni medicinski sistemi, “new age” prakse, i religiozni i tradicionalni rituali i prakse. Istraživanje na reprezentativnom uzorku u Srbiji (N = 1003, Mузраст = 39.01, SDузраст = 16.67),  je otkrilo da je namerno nepridržavanje široko rasprostranjeno, sa životnom prevalencijom od 91,3%. Čak 47% ispitanika je uzimalo antibiotike bez lekarskog recepta, dok je 29% samostalno odlučivalo o terapiji. U pogledu TKAM, 97% ispitanika je koristilo prirodne proizvode ili suplemente, 75% religijske ili tradicionalne običaje, 49% alternativne medicinske sisteme, i 35% “new age” prakse. U okviru fokus grupa, lekari i praktičari TKAM su dali mišljenje o uzrocima ovih ponašanja. Lekari su istakli nedostatak zdravstvenog obrazovanja, nedostatak vremena za pacijente i jednostavnost korišćenja TKAM kao faktore koji utiču na nepridržavanje. S druge strane, praktikanti TKAM su naglasili holistički pristup zdravlju i posvećen odnos prema pacijentima kao razloge za korišćenje ovih pristupa. Kvantitativni nalazi su pokazali da su negativna iskustva s zdravstvenim sistemom, kao što su vređanje, zahtevanje novca ili nedostatak informacija o postupcima koji se sprovode nad pacijentom, najznačajniji prediktor namernog nepridržavanja (β = .19 до .25, p <.001). Što se tiče korišćenja TKAM, pored negativnih iskustava značajnim se pokazuju iracionalna uverenja poput magijskih uverenja o zdravlju (β = .13 до .25, p <.05), sujeverja (β = .19, p <.01) ili verovanja u ekstrasenzornu percepciju (β =.11, p <.01). Ova uverenja su empirijski snažno međusobno povezana u sindrom, a zajedničko im je da im nedostaje baza dokaza, idu protiv prihvaćenih naučnih saznanja ili ontoloških pretpostavki o svetu. U zaključku, ova istraživanja ukazuju na široku rasprostranjenost oba ponašanja i naglašavaju potrebu za intervencijama za njihovo smanjenje. Razmotrićemo ulogu psihologa u identifikovanju, ublažavanju i prevenciji ovih ponašanja.

Keywords: namerno nepridržavanje zvaničnih medicinskih preporuka, TKAM (tradicionalna, komplementarna i alternativna medicina), negativna iskustva sa zdravstvenim sistemom, iracionalna uverenja, magijska uverenja o zdravlju

The use of traditional, complementary, and alternative medicine (TCAM) practices is growing worldwide. To understand the reasons behind this trend, we explored basic psychological variables such as personality traits and thinking dispositions as predictors of TCAM use. A sample representative of the Serbian adult population (N = 1003; 57.6% female; age range: 18-75) completed: 1) TCAM-22, a comprehensive checklist for
indicating lifelong use of 22 TCAM practices such as acupuncture, use of herbal products, meditation/mindfulness, and prayer for own health, 2) HEXACO personality inventory, 3) DELTA inventory assessing the additional personality trait of Disintegration – a tendency towards psychotic-like experiences, 4) REI-8 assessing rational and experiential thinking styles, and 5) the Cognitive Reflection Test (CRT). An average participant used eight TCAM practices during their lifetime (M = 7.92), but there was also a considerable level of variability in TCAM use (SD = 3.30). Personality traits and thinking dispositions were significant predictors of TCAM use, F(10, 992) = 10.70, p < .001, explaining 9.7% of its variance. More use of TCAM was best predicted by high experientiality (β = .16) and high Openness (β = .14), followed by high Emotionality (β = .12) and Disintegration
(β = .11), with low Honesty-Humility (β = -.09) and low cognitive reflection (β = -.06) also contributing to the prediction. Our results suggest that thinking styles and personality traits may play a significant role in the choice of medical treatment and should thus be taken into consideration when planning healthcare strategies.

Rather than following official medical advice, people often succumb to different questionable health practices to improve their health or recover from illness. For example, they may intentionally not adhere to official medical advice by making decisions about their therapy or self-medicating, or use complementary, traditional, and alternative medicine (TCAM). Research from other countries suggests that these two types of behavior are widespread, however, their prevalence in Serbia is unknown. To address this, we asked a nationally representative sample of Serbian citizens (N = 1003) about their lifetime experiences with non-adherence to official recommendations (12 items) and the use of TCAM practices for health reasons (22 items). On average, respondents reported not adhering to 4.01 (SD = 2.94) out of 12 proposed medical recommendations, while 88.9% reported at least one non-adherence. The most prevalent non-adhering behaviors were not going to the doctor when feeling ill (77.6%), taking antibiotics without a prescription (46.7%), and refusing to change unhealthy lifestyle habits (40.4%). The least frequent non-adhering behaviors were not reporting or minimizing symptoms when talking to a doctor (23.6%), self-determining the dosage of the prescribed medicine (16.2%), and avoiding a medical check-up (16.2%). For TCAM practices, respondents reported using, on average, 7.51 (SD = 3.27) out of 22 practices at some point in their life. At the same time, 99.3% had used at least one of the proposed TCAM practices. The most frequent TCAM practices were consuming herbal products (88.8%), using herbal balms, pledgets, creams, or ointments (85.2%), and eating herbs (garlic, houseleek, etc.) for improving health (87.7%). The least prevalent practices were quantum medicine (6.7%), crystal therapy (6.1%), and spiritual healing (4.6%). Even though behaviors covered by the checklists were quite diverse, both instruments proved to be fairly internally consistent – Cronbach’s alpha for non-adherence was ɑ = .79 and for TCAM ɑ = .77, suggesting common latent tendencies. The correlation between lifetime non-adherence to medical recommendations and use of TCAM was r = .29. Based on observed prevalences, clinicians should be advised not to assume a fully compliant patient, since it seems that non-adherence and trying alternatives is more a norm than an exception.

Keywords: prevalence, complementary and alternative medicine, health behaviors, traditional medicine

Although it lacks a solid evidence base, people use traditional, complementary, and alternative medicine (TCAM), and they do so in three distinct ways: 1) for preventive purposes, 2) complementarily to prescribed therapy, and 3) as an alternative to it. While preventive use of TCAM is of least concern, these treatments can sometimes have detrimental interactions with conventional when used as complementary, and especially as an alternative to treatment. Using TCAM instead of conventional treatments can delay efficient cure and decrease the chance of recovery. Previous studies have indicated that the use of TCAM is rooted in the “irrational mindset” (IM) – a composite of irrational beliefs and cognitive biases. However, different ways of using TCAM may not be equally irrational. Here, we explored whether the IM predicts the three ways of TCAM use. Participants from a nationally representative Serbian sample (N = 1003) filled in a set of the IM measures: Medical conspiracy theories (ɑ = .83), Superstition (ɑ = .70), Magical beliefs about health (ɑ = .77), Extrasensory beliefs (ɑ = .77), and Naturalness bias (single item). They also indicated how they typically used different domains of TCAM practices (preventively, complementarily, alternatively, or none). We coded their answers “1” if they indicated that they used a domain in a particular way and with “0” otherwise. We tested the explanatory power of IM variables for the ways of TCAM use within three binary logistic regression models, one for each way of use. The irrational mindset was the most predictive for the alternative use of TCAM (χ2(5) = 40.56, p < .001; Nagelkerke R2 = .07). Those endorsing medical conspiracy theories (OR = 1.48, p = .001) and extrasensory perception beliefs (OR = 1.41, p = .009) were more likely to turn to TCAM alternative to the prescribed therapy. On the other hand, the predictive power of IM was quite weak for preventive (χ2(5) = 14.39, p = .013; Nagelkerke R2 = .02) and complementary use (χ2(5) =18.06, p = .003; Nagelkerke R2 = .02) suggesting these behaviors not to be irrational. Whilst abandoning treatment and turning to TCAM is the rarest scenario (17%), it is the most dangerous one, particularly in case of life-threatening illnesses. This is why health communication interventions must cut deeper and also address its underlying irrational beliefs: endorsing unfounded extrasensory abilities and dismissing official medicine due to so-called “Big pharma conspiracies”.

Keywords: Irrational beliefs, Complementary and alternative medicine, Traditional medicine, Health behaviors

Medical practices outside of conventional medicine can be classified into the broad category of traditional, alternative, and complementary medicine (TCAM). To appeal to people’s biases and play into their irrational beliefs, TCAM practices are often presented so as to appear scientific, for example, through the use of pseudoscientific jargon (e.g. biofeedback or chelation therapy). Their names are strategically crafted to signal that fact – the name should serve as a heuristic of a kind. Drawing from pseudoscientific jargon, we invented five fake medical practices and embedded them in a list of 71 existing TCAM practices. A total of 500 Serbian respondents (73% women, mean age M = 38.59) assessed how familiar they were with all of them. Next, we explored if those who claimed they were familiar with non-existent practices were also (1) more likely to have a positive attitude towards TCAM and use TCAM practices in general and (2) more likely to have the so-called “irrational mindset” (a set of beliefs such as conspiracy mentality, superstition, and biases such as illusory correlation, omission, and naturalness biases). On average, around 22% of people reported having heard of at least one practice that does not exist. Also, the more fake practices participants recognized, the more likely (albeit to a small degree) they were to have a positive attitude towards TCAM (r = .13, p = .003) and to use existing TCAM practices (r = .09, p = .035). Most importantly, the more fake practices they recognized, the more likely they were to hold magical beliefs about health (r = .21, p < .001), and conspiratorial beliefs (r = .14, p = .002), to be susceptible to illusory correlation (r = .11, p = .016), and omission bias (r = .11, p = .010). Once all of these predictors are entered into a regression model, the model significantly predicts familiarity with non-existent practices (F(6, 493) = 4.343, p < .001, R2 = .039), with only magical health beliefs contributing significantly (β = 0.187, p = .004). Our findings suggest that people more prone to non-normative reasoning, with a conspiratorial worldview, and especially those endorsing false beliefs about health tend to rely more on pseudoscientific proxies when navigating the offer of TCAM practices. The fact that they claim having heard about fake practices they have no prior information on, could potentially make them candidates to try different non-evidence-based treatments, thus endangering their health.

Keywords: irrational beliefs, complementary and alternative medicine, health behaviors, traditional medicine

Epistemically unfounded beliefs and biases that are not compliant with normative
rationality and are typically resistant to counter-evidence can be labeled jointly under
the term Irrational Mindset. These different aspects of irrational thinking and reasoning
are usually measured separately, in specific domains – for example, research focuses
either on cognitive biases (e.g., belief bias, base rate bias), or on epistemically unfounded beliefs (e.g., superstition, conspiracy mentality). However, research
suggests these beliefs and biases are interrelated, indicating that they might have a
shared root. This shared core of the irrational mindset can, in turn, be traced back to a
common approach to information processing – one that is characterized by more
intuitive and less analytical thinking. In the present study, we explored (1) whether various aspects of the Irrational Mindset converge toward one latent factor and if so, (2) could this Irrational mindset factor further be tracked to a disposition for less reflective and more intuitive thinking. A sample of 224 panelists (54% females, Mean age = 41.5, SD = 12.64) completed an online set of questionnaires and were remunerated for their participation. We collected data on ten irrational mindset variables, including epistemically unfounded beliefs (superstition, conspiracy mentality, medical conspiracy beliefs, magical beliefs about health, doublethink) and cognitive biases (commitment bias, naturalness bias, belief bias, illusory correlation, and probability reasoning biases). We also assessed thinking dispositions: (1) rational and experiential thinking styles, using Rational-Experiental Inventory (REI), and (2) cognitive reflection using Cognitive Reflection Task (CRT). A principal component analysis on the Irrational Mindset variables clearly indicated a single-factor solution, explaining 31.2% of total variance. All Irrational Mindset variables loaded onto this factor, although cognitive biases had somewhat lower loadings (.31 < w< .44) compared to unfounded beliefs (.59 < w < .83). A multiple regression analysis indicated that 20.8% of the Irrational Mindset’s variance could be explained by thinking dispositions (F(3, 223) = 20.50, p < .001). As expected, Irrational Mindset was predicted by lower cognitive reflection (β = -.34, p < .001) and higher experiential thinking style (β = .29, p < .001), while rational thinking style was not a significant predictor (β = .07, p = .31). Despite the fact that these diverse aspects of the irrational mindset differ both in their content and way of measurement, the obtained pattern of results strongly supports the idea of a shared core for different manifestations of irrationality. We discuss the implications of this “irrational core” as well as its importance for various detrimental outcomes, such as, for example, the use of questionable health practices.

Keywords: irrational beliefs, cognitive biases, thinking styles, irrational mindset, irrationality