Background

The Myers-Briggs Type Indicator (MBTI) is a widely utilized psychometric tool designed to measure individual preferences in understanding the world and decision-making, based on Carl Jung's theories (1). Developed during World War II, the MBTI classifies psychological differences into four dimensions, resulting in 16 personality types. It is extensively applied in psychology and business for hiring, team building, and career selection, helping individuals perform better in various environments (2).

Understanding psychological types is crucial for recognizing conscious tendencies. and these tendencies may be strongly linked to carrier choices. For instance, extroverted intuitive types may succeed in management or business but perform poorly in artistic fields, while introverted thinking types may thrive in mathematics or library sciences but find it challenging to adapt to careers involving high levels of social interaction (1).

In medical education, choosing a specialty is one of the most critical decisions faced by students, as it directly shapes their professional and personal lives. Numerous studies have examined the relationship between personality types and specialty preferences among medical students. Jafrani et al. (2017) evaluated the relationship between personality type and the choice of specialty among 400 medical students from public and private universities in Karachi. They found that the most common personality type among students was ESFP and that personality type would significantly influence students' specialty preferences (3). In contrast, Yang et al. (2016) in a study of 835 psychiatry residents in U.S. universities found no correlation between the students' personality types and their tendency towards psychiatry (4). Similarly, Poursaberi (2016) explored the relationship between personality type and academic achievement among students at Tabriz University of Medical Sciences, indicating a significant inverse relationship between extroversion and academic achievement (5). Stilwell et al. (2000) studying 3,987 medical students across 12 schools, also reported that personality dimensions affect specialty choice: male students with Thinking (T) and Judging (J) profiles preferred surgical specialties, while female students with Introverted (I) and Feeling (F) profiles showed greater tendency toward family medicine (6).

In Iran, several studies have inspected factors influencing specialty choices, but most have focused on non-psychological determinants. Alizadeh et al. (2013) reported that economic factors, especially the job market, alongside individual factors such as personal interest were most influential in specialty choice (7). Shakurnia et al. (2013) found a significant correlation between gender and the capacity of specialty programs (8), whereas their later study (2016) underscored the most important priorities included better work performance, enhanced knowledge and personal interest, with ease, lack of stress, and comfort being least influential (9). Khoroosh et al. (2012) highlighted that 45.4% of residents chose specialties solely due to personal factors, 14.9% owing to external factors, and 39.74% based on both (10). Zarghami et al. (2003) further noted that the most influential factors were the desire to help people and the scientific content of the specialty (11). Nevertheless, despite these findings, very few Iranian studies have examined the role of personality type in the choice of specialty and none have been reported in Yazd.

Given this gap, the present study was designed to explore the relationship between personality types, as measured by the MBTI, and specialty preferences among students at Shahid Sadoughi University of Medical Sciences in Yazd. This issue is particularly important since selecting a specialty not only shapes the physician’s career path but also influences the distribution of the healthcare workforce. Beyond individual skills, aligning psychological traits with the chosen field is likely to contribute to greater professional satisfaction and effectiveness.

Based on previous international findings (6), we hypothesized that personality type would significantly influence specialty choice, particularly when career-related factors were excluded.

Objectives

This study investigates the relationship between medical students’ personality types and their specialty preferences, highlighting how self-awareness and personality–career alignment can enhance decision-making and future professional success.

Methods

This study employs a descriptive and analytical cross-sectional design, with data collected via a questionnaire administered to students. Ethical approval was obtained from the National Committee for Ethics in Biomedical Research, under the code IR.SSU.MEDICINE.REC.1397.16.

Data collection: The study included all medical students in their internship (both scholarship and
self-funded) in 2018, totaling 200 individuals at Yazd University of Medical Sciences, with no sampling conducted. The exclusion criteria were lack of consent from students to participate in the study or incomplete questionnaires. After explaining the research objectives, confidentiality, and the exclusive use of findings for research purposes, one of the authors distributed the paper questionnaires among the students. Students were then asked to carefully read and answer all questions in the questionnaire as well as to ask the researcher any questions if they faced any ambiguities. Incomplete questionnaires were excluded from the study.

MBTI Questionnaire: To ascertain personality types, the Myers-Briggs Type Indicator (Form M) was employed, which is an internationally recognized questionnaire with confirmed validity and reliability (12). The MBTI was selected for its widespread use and practicality in educational and career-related research. Despite some limitations, it provides a structured and accessible approach to exploring personality preferences, making it suitable for examining potential links with medical specialty choice among students. The validity and reliability of the Persian translation of this questionnaire, which is also utilized in the current study, have been examined by Poursabri (5). Similar to several other studies, Poursaberi referred to Yaghoubi Beglar’s (2007) master’s thesis for the validation and reliability of the questionnaire. He reported construct validity as confirmed and reliability coefficients for the subscales ranging from 0.45 to 0.87 in the long form and 0.66 to 0.89 in the short form (13). This questionnaire tests four bipolar personality types (Extraversion - Introversion, Sensing - Intuition, Thinking - Feeling, and Judging - Perceiving) on a continuous scale, ultimately presenting 16 personality types (Table 1). The questionnaire consists of 93 questions split into four sections. In the first and third sections, the individual selects the option that best represents their dominant state, while in the second and fourth sections, they would select the option they prefer in terms of meaning and concept, without considering their current state. Scoring was carried out according to the standard MBTI guidelines. Responses for each item were assigned to one of the two opposing preferences E or I, S or N, etc. The number of responses indicating a preference for Extraversion, Sensing, Thinking, and Judging were then summed up separately to determine the dominant preference for each dichotomy.

Table 1. Abbreviations of Personality Types

In these 16 personality types E stands for Extraversion, S represents Sensing, T reflects Thinking, J denotes Judgment, I stands for Introversion, N shows iNtuition, F represents Feeling, and P stands for Perception.

Data Analysis: The collected data were entered into SPSS software version 21 and analyzed using appropriate statistical methods, including descriptive statistics (frequency indices and relative percentage) as well as a suitable statistical test (Chi-square test). A significance level of 0.05 was considered.

Results

A total of 185 students participated, with 53% being female and 79.5% being scholarship students. Among them, 147 (79.5%) were scholarship students and
38 (20.5%) were self-funded. The majority of the participants were from the entry years 2013 (32.6%), 2012 (29.3%) and 2011 (28.7%).

Considering personality dimensions, 48.1% were extroverted and 51.9% introverted; 35.7% intuitive and 64.3% sensing; 53% thinking and 47% feeling; and 68.1% judging and 31.9% perceiving. The most frequent personality types were as follows: ISTJ (20%), ESTJ (12.4%), and ESFJ (8.1%).

Of the 185 students who initially entered the study, 176 completed all three series of questionnaires. Nine students withdrew after completing only the first series (personality type) as they stated that they did not intend to pursue a specialty program. One student also withdrew following the second series without responding to the third. Hence, the number of participants included in the analyses has not been identical across all sections of the results. When asked about future career paths, 124 students (67%) chose the clinical path, 15 (8.1%) the educational path, and 21 (11.4%) the managerial path, with 25 (13.5%) being indecisive.

When career factors such as income and status were taken into account, the most frequently chosen specialties were radiology (17.8%), dermatology (14.6% and ophthalmology (12.4%). Male students predominantly chose surgery, orthopedics, and ophthalmology, while female students favored radiology and dermatology. A significant association was found between specialty choice and personality type (p=0.001) (Table 2).

Table 2. Frequency distribution of specialty choices considering job-related factors by personality type

In these 16 personality types E stands for Extraversion, S reflects Sensing, T represents Thinking, J denotes Judgment, I shows Introversion, N indicates intuition, F stands for Feeling, and P represents Perception.

When choices were based solely on personal interest, the most common specialties included general surgery (15.7%), cardiology (10.8%), and internal medicine (9.7%). Male students mostly selected general surgery, cardiology, and orthopedics, while female students opted for internal medicine, cardiology, and gynecology. No significant correlation was found between personality type and specialty preference based on personal interest (p = 0.698) (Table 3).

Table 3. Frequency distribution of specialty choices solely based on personal interest by personality type

In these 16 personality types E stands for Extraversion, S reflects Sensing, T represents Thinking, J denotes Judgment, I indicates Introversion, N shows intuition, F stands for Feeling, and P represents Perception.

Nevertheless, no significant gender differences were observed in the distribution of personality types or dimensions (p > 0.05). Ultimately, no significant differences emerged in specialty preferences between scholarship and self-funded students (p > 0.05). The distribution of career path choices by personality types has been presented in Table 4.

Table 4. Frequency distribution of gender and career path selection by personality type

In these 16 personality types E stands for Extraversion, S represents Sensing, T stands for Thinking, J shows Judgment, I denotes Introversion, N indicates intuition, F reflects Feeling, and P stands for Perception.

Discussion

This study aimed to explore the relationship between personality types and the tendency towards specialized fields among medical students at Shahid Sadoughi University of Medical Sciences in 2018. In conclusion, this study of 185 students indicated that general surgery, cardiology, and internal medicine were the most preferred specialties based on personal interest, while radiology, dermatology, and ophthalmology were favored when considering job-related factors such as income and status.

The most common personality types among the students were ISTJ, ESTJ, and ESFJ. Significant correlations were found between gender and specialty preferences, both for personal interest and job-related factors. Further, a significant correlation existed between personality types and specialty preferences based on
job-related factors, but not for personal interest. No significant differences were found between self-funded and scholarship students in their specialty preferences.

Comparing these findings with previous studies, Shakurnia et al. (2013) reported a significant correlation between male and female residents’ specialty preferences at Jundishapur University of Medical Sciences (8). This is in accordance with the gender-related findings of the present study. Jafrani et al. (2017), in a study on MBTI and specialty choice among students in Karachi, concluded that personality type significantly affects students' specialty preferences (3). While this study also found a significant correlation between career paths and the personality dimensions of students, the present study did not. This difference may reflect variations in job conditions across clinical, educational, and managerial paths in Iran, with clinical paths promising better income and job status.

Stilwell et al. (2000) examined 3987 medical students across 12 medical schools. They found correlations between personality dimensions and specialty choice (6), which is in line with the present findings regarding job-related specialty preferences. Yang et al. (2016) reported no correlation between personality type and preference for psychiatry among US residents (4), which is in accordance with our findings regarding personal-interest-based choices but not with job-factor-based choices. This consistency could be explained by the significant role of personal interest in selecting a specialty among U.S. residents. Note that in this study the most preferred specialties considering job-related factors (income, status, leisure, ease) were radiology, dermatology, and ophthalmology, whereas the most preferred specialties based solely on personal interest were general surgery, cardiology, and internal medicine. This discrepancy highlights the importance of job-related factors in specialty selection among students and reveals that many students choose their specialty contrary to their personal interests (14).

Freeman developed a guideline for selecting medical specialties based on personality types (15). A comparison of this study's findings with Freeman's guideline indicates that the specialty preferences of individuals with the following four personality types were consistent with the guideline:

• 7% of individuals with the ESFP personality
  type chose General Surgery.
• 6% of individuals with the ESTP personality
  type chose General Surgery.
• 2% of individuals with the INFJ personality
  type chose Cardiology, and another 22.2% chose General Surgery.
• 2% of individuals with the ISFJ personality type chose Ophthalmology.

The limited alignment between students’ specialty preferences and Freeman’s MBTI-based guideline warrants further contextual interpretation. This discrepancy may be attributable to cultural norms, structural constraints in specialty training availability, as well as strong economic or social incentives
that overshadow personality fit. Further, lack of systematic career counseling and limited exposure to personality-guided decision-making frameworks may contribute to this misalignment in the Iranian medical education context.

The marked divergence between specialty choices based on personal interest and those influenced by career-related factors reflects a paradox. While students may initially prefer specialties aligned with their interests and potentially their personality traits, practical considerations seem to override these preferences. This suggests that systematic pressures and future job conditions significantly shape specialty decisions, sometimes contrary to students’ intrinsic motivations.

This study demonstrated that medical students’ specialty preferences are influenced by a complex interplay of personality types, gender, and career-related factors. The findings highlight the significance of implementing structured career counseling programs and incorporating personality assessments (such as the MBTI) into medical education. This is particularly important along the early clinical years, in order to enable students to make more informed specialty choices based on a clearer understanding of their abilities, interests, and the realities of the job market. Further, the development of personalized decision-support tools tailored to the cultural context and healthcare system of Iran could facilitate more deliberate specialty selection. Such interventions may ultimately contribute to greater job satisfaction and enhanced workforce productivity in the long run.

Limitations: One limitation of this study was the use of the Myers-Briggs Type Indicator (MBTI), which despite its popularity in educational and career guidance contexts, has faced criticism regarding its psychometric robustness. Another limitation of the study was related to the validity and reliability of the Persian questionnaire, which had been established in previous studies; some subscales revealed a low reliability coefficient (0.45).

Although this study employed a census approach and included all medical students at the university, the single-center design may restrict the generalizability of the findings. Nevertheless, the alignment of this study's findings with those of other studies may indicate the validity of the obtained results.

Conclusion

This study examined the relationship between personality types and specialty preferences among medical students at Shahid Sadoughi University of Medical Sciences in 2018. According to the findings, general surgery, cardiology, and internal medicine were the most preferred specialties based on personal interest, while radiology, dermatology, and ophthalmology were favored for job-related factors such as income and status. The most common personality types among the students were ISTJ, ESTJ, and ESFJ.

Significant correlations were observed between gender and specialty preferences, both for personal interest and job-related factors. Further, a significant correlation existed between personality types and specialty preferences based on job-related factors, but not for personal interest. No significant differences were noted between self-funded and scholarship students in their specialty preferences.

Comparison of these results with previous studies highlight the complex interplay between personality, gender, and career-related considerations in shaping specialty choices. The study emphasizes the importance of students understanding their interests, abilities, and future job conditions to make informed decisions. Thus, students may make use of available tools to better understand their personality and make decisions accordingly. Medical students can also benefit from systematic counseling programs that help them integrate self-awareness of their personality and interests with practical considerations about job market. Such support can promote informed decision-making, improve professional satisfaction, and ultimately boost the quality of healthcare workforce.