Influence of Dark Triad Personality on Attitudes Toward Brain Death, Organ Donation, and Futile Therapy

Introduction

The Dark Triad, first introduced in 2002 by Delroy L. Paulhus and Kevin M. Williams, is a cluster of 3 personality traits: narcissism, psychopathy, and Machiavellianism [1]. Narcissism is associated with grandiosity, entitlement, and superiority; psychopathy with high impulsivity and low empathy; and Machiavellianism with pragmatism, exploitation of others, and cynicism [1]. Each one of these features is socially perceived negatively, but psychopathy and Machiavellianism are seen as the most aversive, often perceived similarly and associated with arrogant and manipulative behavior [2].

Since the first articulation of the Dark Triad concept in scholarly research, numerous studies have been conducted to investigate its structure and impact on social, medical, and behavioral aspects. It has been shown that individuals scoring high on Dark Triad traits tend to make utilitarian decisions in morally difficult situations [3]. However, studies have shown that psychopathy and Machiavellianism predicted utilitarian choices when they serve the individual’s self-interest [4]. This finding can be the reference point for exploring DTS in medical fields, where moral dilemmas are part of clinicians’ and patients’ everyday experience. Researchers also point out that possession of Dark Triad features is connected to poor health practices, such as low physical activity [5]. People with Dark Triad traits demonstrate risky behaviors more frequently – high-risk activities, such as problematic internet use and aggressive behavior, are more common among individuals who score higher in these traits, especially those with Machiavellian/narcissistic and Machiavellian/psychopathic profiles [6]. These studies show that Dark Triad traits can play a significant role in various beliefs and actions. In recent years, researchers noted that DTS traits can influence the decision to receive COVID-19 vaccination [7,8]. Studies conducted on intensive care unit nurses suggest that female nursing staff who score higher on these traits feel stronger death anxiety [9]. Scientists have also noted that these features, especially narcissism, are associated with counterproductive work behaviors and burnout among medical staff [10]. These studies show that Dark Triad personality can affect certain aspects of medical practice.

Although the Dark Triad has been the topic of many studies, there is still a lack of research focusing on associations between these traits and end-of-life medical dilemmas. The connection between DTS traits and attitudes toward organ donation, brain death, and futile therapy would be a unique contribution to many medical fields, where it could give clinicians enhanced understanding of their patients’ beliefs, decisions, and motivations towards them, caused by their personality traits. The aim of this study was to determine if possessing features of the Dark Triad has an impact on individual’s perception of futile therapy, organ donation, and brain death, exploring potential associations of these traits with individuals’ beliefs connected with end-of-life dilemmas.

Material and Methods

STUDY DESIGN:

Forty-eight second- and third-year paramedic and midwifery students (the ST group) were recruited for this cross-sectional exploratory survey study. Data were collected during regular class sessions within a single academic term, and all students were invited to participate, under the same conditions. A brief standardized explanation of the study was provided, after which students gave voluntary consent and completed the anonymous digital questionnaire individually in the classroom. Moreover, the survey was distributed via Facebook groups and channels to collect data from non-medically (NM) educated individuals (n=88). The research was conducted on groups of people interested in completing the questionnaires on a survey-by-survey basis. This was a pilot study. The sample does not represent a complete cross-section of society, and the data collected were intended to outline further directions in research on personality and the understanding of ethical aspects of intensive care.

All participants were asked to provide consent for participation. Each participant was asked to fulfill a short online survey containing demographic questions, The Dark Triad Scale questionnaire (in Polish adaptation [11]) with range of 9–45 points for each subscale and at the end of the survey students answered 4 questions (in ‘1=I strongly disagree’ to ‘5=I strongly agree’ scale) concerning ethical aspects of intensive care:

The term ‘futile therapy’ in Q4 refers to medical care that is not beneficial for a patient’s overall health and quality of life.

ETHICS STATEMENTS:

The study was conducted in accordance with the Declaration of Helsinki (as revised in 2024). Participation in the study was completely voluntary and anonymous; no personal data enabling the identification of participants were collected or stored. According to Polish regulations on non-interventional research with adult participants, anonymous questionnaire studies that do not collect sensitive personal data or involve medical procedures are exempt from mandatory review by a bioethics committee. This exemption is specified in national research ethics guidelines and is reflected in Powiślański University’s internal policy on student survey research. Because the study involved voluntary, anonymous completion of a standard questionnaire without any clinical intervention, it met the criteria for exemption from formal ethics committee approval.

Pursuant to the Act on the Medical Profession in force in Poland (Journal of Laws 1997, No. 28, item 152), bioethics committees review medical experiments (defined as research that impacts the health of participants). The regulations of bioethics committees operating in Poland, available online, exclude survey research from review. The Powiślańska Academy of Applied Sciences does not have a bioethics committee, so the researchers intended to contact the Committee at the University of Warmia and Mazury in Olsztyn (the employer of the co-authors of this article). The committee’s regulations explicitly state that survey research does not require an opinion.

STATISTICS:

Statistical analysis was performed and the figures were obtained with jamovi software. Non-parametric tests were used (Mann-Whitney U test, chi-square test, Spearman’s rho) because the survey responses involved ordinal data (Likert-scale items), and several variables’ distributions deviated from normality in this relatively small sample. These tests do not depend on assumptions of normal distribution or equal variances, making them suitable for comparing groups and examining correlations in datasets of this size and nature. Their use helps ensure that the statistical analysis remains reliable and appropriate for the data collected.

Since males were underrepresented in the NM group, the results collected only from females (n=75) were subsequently analyzed with clustering. Cluster analysis was limited to women only to reduce the potential influence of gender, which could confound the analysis. With the currently collected data, it was not possible to reliably assess the responses provided by men (the group was too small). Primary, exploratory Principal Component Analysis (PCA) tests were performed with all DTS traits and Q1, Q2, Q3, and Q4 results. Since the result of the KMO test for Q4 was 0.454, it was excluded from further analysis. The KMO value is a measure of the sampling utility. For KMO test values <0.5, the data’s utility in the PCA statistic is very low and should be rejected. PCA for NM females was performed with subsequent K-means clustering (number of clusters −1) in jamovi MEDA plugin.

Results

GENERAL RESULTS:

General results are presented in Table 1. Of all DTS traits, Machiavellianism was the highest in both groups. No difference in DTS is observed between the ST and NM groups, but there was a significant difference in attitudes toward becoming an organ donor in case of brain death – students were more likely to consent, but the size effect was small (r=0.203). The NM group consisted of younger participants and had more females than males. Among students there was a weak positive significant correlation between the level of Machiavellianism and the opinion that futile therapy is an unethical practice (rho=0.293, p=0.043). This correlation was much more pronounced (moderate correlation) in females (rho=0.481, p=0.027) and it is not significant in males (rho=0.180, p=0.370). No other correlation was observed in this group. This finding was not present in the NM subgroup. Nevertheless, different correlations have been revealed. Among non-medically educated individuals, Machiavellianism was negatively correlated (weak correlation) with answers to Q3 ‘Each patient should be intensively treated…’ (rho=−0.227, p=0.034), meaning that high level of Machiavellianism is associated with a lower tendency to continue futile therapy. This finding is particularly significant (moderate correlation) among NM females (rho=−0.303, p=0.008). Moreover, in this subgroup the level of psychopathy was associated (a weak positive correlation) with answers to the question ‘Brain death does not exist’ – Q1 (rho=0.233, p=0.044). This correlation was not present in the combined (males and females) NM group.

MULTIVARIATE ANALYSES FOR NON-MEDICALLY EDUCATED FEMALES:

Exploratory PCA (with data limited to NM females only) revealed 2 significant dimensions with cumulative variance 61.2%. Loadings of components are presented in Table 2. Clustering divided the group into 3 clusters (Figure 1). Characteristic of each one is presented in Table 3. Post hoc analysis revealed statistically significant differences between all clusters for Machiavellianism and narcissism, while there were no significant differences between cluster 2 and 3 for psychopathy. For Q1, there was a difference between clusters 1 and 2, as well as 2 and 3, with no difference between clusters 1 and 3. Moreover, for Q3 there is a difference between clusters 1 and 3, as well as 2 and 3, with no difference between clusters 1 and 2 (Figure 2).

Discussion

Our study included medical students and non-medical participants. There were no significant differences in levels of DTS between these groups. We found a positive correlation between the level of Machiavellianism and belief that futile therapy is an unethical practice in the ST group. We observed a negative correlation in the NM group between Machiavellianism and the opinion that every patient should be treated until the end of life. Medical students were more likely to become organ donors in case of brain death. Non-medically educated females were also divided into 3 clusters, depending on the level of DTS.

Our study has several limitations. First, the ST and NM groups were not equal – the ST group was almost twice as large as the NM group. Second, the sample consisted mainly of females, who tend to score lower on DTS [1]. In further analysis, we focused only on female participants, as there is a lack of information about males. Third, the sample included a total of 136 participants, which is relatively small. Fourth, data were collected through an online form, which could lead to self-report bias, including social desirability bias. Studies show that people can lie on the Dark Triad Scale [12]. Although our study collected completely anonymous data, participants had no incentive to lie. Furthermore, another study demonstrated a relationship between personality (Light Triad Scale) and understanding the ethical aspects of intensive care [13]. Also, our study excluded older participants and individuals without internet access, which may have introduced online recruitment bias and limited the representativeness of the sample. Fifth, participants, especially from the NM group, could have problems with understanding survey questions, especially Q4. Individuals in the NM group could have misunderstood the phrase ‘futile therapy’ – they may not have been aware that it means therapy that is not beneficial for patient health, which could have affected the results. Finally, given the exploratory design of the research, the findings should be interpreted as hypothesis-generating only.

Some researchers point out that healthcare staff score lower in Dark Triad traits than the general population, which can be caused by various factors, such as selection bias favoring empathetic individuals and an environment that encourages prosocial behaviors [14]. Scientists from Iran suggest that lower levels of dark personality traits may result not only in better patient–doctor relationships, but also improved communication and cooperation between medical team members [14]. A study from Slovakia found that people preparing to work in helping professions (including medical professions) do not score high in dark personality traits [15], but our study did not find any significant differences in dark personality traits levels between groups. This may be because the that NM group was mainly composed of females, who tend to score lower in these traits [1,16].

We expected that individuals who scored higher in Machiavellianism would not consider futile therapy an unethical procedure. However, results in the ST group revealed a positive correlation between cynicism and perceiving futile therapy as unethical practice. This association was stronger among female participants, and among males there was little to no correlation, and this association was not present in the NM group, perhaps because the meaning of the phrase ‘futile therapy’ was unclear for individuals without medical knowledge. However, in the NM group, there was a negative correlation between Machiavellianism and belief that every patient should be treated until the end of the life. As in the ST group, this correlation was stronger among women. These results suggest that female Machiavellians favor limiting futile therapy. No previous research has directly focused on the influence of this trait on attitudes toward non-beneficial treatment.

We did not find significant correlation between Dark Triad personality traits and willingness to become an organ donor. However, there was a difference between ST and NM groups – students were more likely to become an organ donor in case of brain death. A 2022 meta-analysis showed a pooled rate close to 70% of students willing to become an organ donor after death [17]. Other research conducted in different countries showed that this percentage is lower among the general population [18–20]. These studies support our results. Other factors that can affect willingness to become an organ donor are religion, spiritual beliefs, family values, and age [17,18,21].

In the present study, non-medically educated females were divided into 3 clusters. The first consisted of individuals with the lowest level of Dark Triad personality traits, the second cluster showed intermediate levels of these traits, and third cluster had the highest level. Respondents in clusters 1 and 3 believed that brain death exists, but those in cluster 1 indicated that every patient should be intensively treated until the end of life, even if it does not carry any benefits. In contrast to them, those in cluster 3 believed that futile therapy should not be administered to every patient. Cluster 2 respondents expressed the opinion that brain death does not exist and every patient should be treated until the end of life. These results suggest that people with the highest scores of Dark Triad traits report higher empathy-related attitudes regarding end-of-life medicine. However, previous research shows that these traits are associated with lower levels of empathy [22]. Differences between our results and those of other researchers can be explained as follows: (1) other studies did not focus directly on the connection between DTS and aspects that we examined; (2) our clustering was conducted only on female participants, who tend to score lower in these traits than males [1]; and (3) our study explored attitudes toward empathy-related topics, rather than levels of empathy among participants.

Our findings can be helpful in discussions about ethical topics in medical care, especially the ones that occur in intensive care units. They can give better understanding of patients’ attitudes toward organ donation or limitation of futile therapy. Even though our results reflect attitudes rather than decisions, they may be helpful for clinicians when discussing these matters with patients and their relatives to prepare for possible reactions.

Future research in this field should include males without medical education and larger samples. Our results suggest that opinions on end-of-life topics can be affected by personality. Dark Triad traits seem to be related with the examined aspects mainly among women. Thus, communication of medical staff with patients’ relatives needs to be carefully planned. The possible beneficial role of psychologists in intensive care is strengthened by this study. Future medical professionals are not free from their psychological background, which can affect their future work. There is a need for more research in this field, since those with low levels of DTS traits may experience more distress concerning end-of-life decisions.

Conclusions

Personality traits described by the DTS are related to the perception of selected ethical aspects of intensive care, especially among females. Understanding the limitations of futile therapy as a beneficial approach to the patient correlates with the level of Machiavellianism. Individuals who deny the existence of brain death exhibit intermediate levels of Dark Triad traits.