No Tendencies of Personality Traits in Blood Groups: a cross-sectional study conducted on Bangladeshi people.


 No studies to date came up with fruitful consequences regarding if or not there is a relationship between blood groups and personality traits rather providing most conflicting, floundering, discrete, equivocal outcomes. Traditionally, Japanese and Korean people support the conception that there are natural inclinations of personality traits in blood groups. Our study aims to explore the rationality of this conception that personality traits and blood groups are interrelated. However, responses of the participants were collected using 50 items big-five factor personality inventory developed by Goldberg: Extraversion, Agreeableness, Neuroticism, Conscientiousness, Intellect (Openness to experience). A two way multivariate analysis (MANOVA) was performed on total 148 participants including 85 males and 65 females using IBM SPSS Statistics version 26. MANOVA results revealed that neither the significant main effect of blood groups [F (15,414) = 1.102, p > 0.05] nor had the significant interaction effect of blood groups and gender [F (15,414) = 1.111, p > 0.05] on the combined dependent variables. But this study found significant main effect of gender on the combined dependent variables [F (5,136) = 4.520, p = 0.001, (1-β) = 0.967, η2 = 0.143].This present study does not support the idea that there is significant relationship between blood groups and personality traits. But the idea that male personality significantly differs from female personality is well-supported by this study.


Introduction:
The notion of having possible relationship between blood types and personality traits is not noble, which is presumed to start coagulating since the discovery of ABO blood groups by Landsteiner in 1901 (Hobgood, 2011). But till now, no scienti c solidarity has been achieved with regards to this notion.
Scientists have been searching the connection of personality traits being the re ection of the speci c patterns of thoughts, feelings and behaviors of an individual (Diener & Lucas, 2021). Some previous studies mentioned that genetic materials explain 50% of what personality traits a person will have and socio and cultural factors, environmental factors such as stressful life condition, parenting style, socioeconomic status etc. in uence the remaining thereof (Khaledian et al., 2013;Tsuchimine et al., 2015). But, which genes or genetic materials have guidance on the development of personality traits is still under scrutiny(Wu et al., 2005). As blood groups are genetically determined and can easily be identi ed, therefore, scientists are much more interested about blood groups (Rogers & Glendon, 2003). Tsuchimine et al., (2015) anticipated that ABO genes could have indirect effects on personality traits, demonstrating the hypothesis of Hobgood, (2011) suggesting ABO genes are in linkage disequilibrium with DBH (Dopamine beta hydroxylase) genes. Supporting that, Furukawa, (1927) reported blood groups are signi cant determinant of temperament. In addition, Japanese and Korean traditionally believe the possible in uence of blood groups on personality traits, mental state, temperament and harmony with others (Hobgood, 2011;Pisk et al., 2019). Their belief is not completely irrational because blood groups were found to associate with certain diseases having small to moderate impact on personality characteristics of an individual. For instance, some previous studies showed the linkage of blood groups with peptic ulcer, cancer, cardiovascular disease, stress response-related immune disease, smoking prevalence etc. Presumably, these diseases might have linkage with speci c personality traits such as depression, anxiety, which explain the likelihood of having relationship between blood groups and personality traits (Hobgood, 2011;Kumar et al., 2021;Tsuchimine et al., 2015). Furthermore, psychological and mental problems having hereditary connection with blood groups are thought to arise from the weakness in personality building, which also suggest there could have tendencies of personality traits in blood groups (Alsadi, 2020).
From the beginning, a number of personality testing instruments have been used to unfold the possible relationship between blood groups and personality traits. Among them some used two dimensions of personality (such as Cloninger's low Reward Dependence vs high Reward Dependence, high Anger vs low Anger etc.), some used three dimensions of personality (such as Eysenck's Personality Theory), some used ve dimensions known as ve factor model (such as NEO-PI, Goldberg's instrument), a recent study used seven dimensions of personality (such as Temperament and Character Inventory) and so on. As compared to other instruments, ve factor models are widely accepted and used because of their capability of adjusting other structures and arranging a range of characteristics which are bene cial in clinical psychology (Paul et al., 1992;Rogers & Glendon, 2003).
Review of some previous studies showed the inconsistent outcomes of the personality assessments.
Some studies claimed they obtained signi cant relationship between blood groups and personality traits while some studies stated they did not observe any inclination of personality traits in blood groups. Cramer & Imaike, (2002) at the University of Windsor in Southwestern Ontario, Canada, studied 419 psychology undergraduates using 60-items NEO-PI. They reported that they did not get any signi cant relation between blood groups and personality traits. In the same year, Rogers & Glendon, (2003) came up with similar result that they did not get any relation between and personality traits. Unlikely here they used Goldberg, (1992) instrument instead. In Asia for rst time, Wu et al., (2005) conducted personality assessment in a large scale with 2681 participants using Neuroticism Extroversion Openness Personality Inventory Revised (NEO PI-R). But the consequence is in harmony that no relation was found between personality traits and blood groups. Nahida & Chatterjee, (2016) reported that they did also nd no correlation between blood groups and personality, that is parallel to the outcomes described above, although they used Eysenck's Personality Questionnaire Revised (EPQ-R) and sample size was small (N = 100). Alsadi, (2020) at Al Istiqlal University, Jericho, Palestine, studied 337 physically healthy students using Eysenck Personality Inventory and found no positive relationship between personality and blood groups. The conclusion that no relation exits between blood groups and personality traits are further supported by the outcomes of a recent study conducted by Kumar  in different blood types [P = 0.04]. But they did not obtain signi cant relationships of conscientiousness, neuroticism, agreeableness with different blood types. In the same year, Tsuchimine et al., (2015) conducted personality assessment using Temperament and Character Inventory (TCI). They reported that they observed a signi cant association between ABO blood group genotypes and personality traits in a large number of healthy Japanese subjects [N = 1427, P = 0.001]. They showed blood group A had signi cantly higher Persistence than blood groups B and O [P = 0.032].
As to describe the relationship between gender and personality traits, some previous studies support the statement that personality traits of males signi cantly differ from that of females is supported Cramer & Imaike, (2002), Kumar et al., (2021) and Rogers & Glendon, (2003). For instance, Cramer & Imaike, (2002) reported that as compared to females, males score signi cantly higher on both Agreeableness and Neuroticism. This outcome is partly supported by Kumar et al., (2021). They stated that females comparatively score higher in agreeableness than males. On the other side, some studies reported that they did not nd any signi cant relation between gender and personality traits. However, there is still no scienti c consensus whether personality traits are independent of blood groups or not because research consequences absolutely consistent with that of other researches done earlier have not been obtained yet, which craves for the increment of the number of well-planned research on this eld. The more research, the more chance to reach out the suitable conclusion. Our study is another attempt to nd out the conclusive statement. The aims and objectives of this present study is to check the rationality of the thoughts of having relationship between blood groups and personality traits.

Participant and Procedure:
A cross-sectional survey was carried out in Bangladesh using Goldberg, (1992) instrument based on online platform during covid-19 pandemic. Given a message through Facebook messenger to take part in this survey continued for 17 days, More than 200 randomly selected individuals were invited and instructed to complete the Google form of 50 items big ve questionnaire sent them with the same message. They were assured to keep their data con dential and requested to choose blood group "Don't know" when there is a confusion aroused regarding correct blood type. Of all invited to participate, 152 individuals responded, from them four individuals with blood group option "don't know" were excluded out of the actual data set, Therefore, actual case number were 148 among them 57% male and 43% female, 23% A, 32% B, 12% AB, 33% O, age of them ranging from 18 to 30 [ Table 1]. where for positive personality dimensions: Extraversion, Intellect, Agreeableness, or Conscientiousness, maximum score (4) was given for strongly agree and minimum score (0) for strongly disagree and for Neuroticism, maximum score (4) was considered for strongly disagree and minimum score (0)

Statistical treatment of data:
Responses of the participants were primarily collected in an excel sheet and further processed using IBM SPSS program 26. A chi-square test for independence with α = 0.05 was conducted to assess if gender (male, female) was related to blood group of an individual, and a two way multivariate analysis of and most psychometricians agreeing with the notion that a cronbach's alpha value of 0.70 is acceptable, both the obtained AIC and alpha values for each of ve scales were enough to prove the adequate internal consistency for the 8-items of these scale, although agreeableness scale is still under questions due to its alpha value (0.57) less than acceptable value (Islam, 2020) [ Table 2]  group A individuals did higher score than blood group AB and O while did lower score than blood group B. Then again, blood group A had highest score on Conscientiousness and Neuroticism than blood group B and O while lowest score than blood group AB. On Intellect, blood group A had lowest score than all other blood groups.
Blood group B had highest score on Extraversion, Conscientiousness, Neuroticism compared to blood group O while lowest score compared to blood group A and AB. In addition, blood group B had highest score on Agreeableness and Intellect compared to all other blood groups.
Blood group AB had highest Conscientiousness score and lowest Neuroticism score compared to all other blood groups. This blood group individual had highest score on Extraversion than blood group B and O while lowest score than blood group A. Then again, blood group AB had highest score on Intellect compared to blood group A and O while lowest score compared to blood group B.
Blood group O had lowest score on Extraversion, Conscientiousness, Neuroticism compared to all other blood groups. This blood group individual had highest score on Agreeableness compared to blood group AB while lowest score compared to blood group A and B. Then again, compared to blood group A, blood group O had highest score on Intellect but had lowest score compared to blood group B and AB. Observed power for the main effect of blood group was averagely 29.6%, ranging from 14% (Conscientiousness) to 44% (Agreeableness). [ Table 4] Table 4 Post-hoc tests results Dependent variables (DV) with observed power, Blood group (I&J), Mean difference (MD), Signi cance value (p), 95% con dential interval. Based on observed mean The error term is Mean square (error) = 13.013 No signi cant interaction effect of gender and blood groups was observed on ve personality dimensions. However, on Extraversion, blood group AB male scored highest and blood group AB female scored lowest. On Agreeableness, blood group B and AB male did high and low score respectively. Then again, blood group AB male and O female did high and low score respectively on Conscientiousness and Neuroticism. On Intellect, blood group B male and blood group A female scored highest and lowest (Table 5). Observed power for interaction effect of gender and blood group was averagely 31.6%, ranging from 14% (Conscientiousness) to 60% (Intellect). [ Table 5] Discussion: This present study suggested that there is no relationship between blood groups and personality traits. Interaction effect of blood groups and gender on personality traits was insigni cant while gender wise difference in personality traits was signi cant.
The nding that personality trait is independent of blood groups is supported by several previous studies directing no relationship between blood groups and personality traits exists (  cognitive ability etc. greatly in uence the personality traits (Alsadi, 2020;Tsuchimine et al., 2015). Since the formation of personality traits is not completely free from environments or surroundings experienced by a growing individual, reaching out a conclusive statement that whether or not there is a relationship between blood type and personality traits will therefore be very di cult and cumbersome. To obtain the exact outcomes regarding if or not there is relationship between blood type and personality traits, the study should be conducted in a large scale, kept all potentially in uencing environmental factors in consideration.
Gender-wise comparisons in personality traits revealed males scored signi cantly higher than females on This present study showed that blood group is independent of gender. Previously it was indicated that blood group is independent of age and ethnicity (Patil et al., 2016). On the contrary, a past study found that blood group is not independent of gender (Cramer & Imaike, 2002).
As to the strength of this study, participants were recruited randomly from all over the country, stayed apart from each other which subsided the intervention of a participant in responses of others as observed in conference, seminar, or any program. Participants were provided enough time to think about themselves, helped them to give correct answers.
As to the limitations of this study, sample size was not so large enough. A pilot study was not conducted which could have assisted to check the reliability and consistency of the questionnaire before the nal study. Participants selected their blood groups based on their own knowledge. No blood group tests were conducted to check the accuracy of self-reported blood groups but respondents were instructed to select the option "Don't Know" if there any confusion.
Future study should be conducted with large sample size having equal number of male and female, taken all potential environmental, social, cultural factors in consideration. Blood groups of all participants should be tested to ensure the accuracy. Before performing nal study, a pilot study should be conducted to certify that questionnaire is well assorted and justi ed to achieve acceptance.

Declarations
Acknowledgement: The main author, Tahsin Ahmed Rupok, greatly acknowledges all those who participated in this study and supported the author for conducting this research.
Author's Contributions: Tahsin Ahmed Rupok conceived and designed this study and performed all statistical analysis. Material preparation, Data collection were performed by Tahsin Ahmed Rupok, Bayezid Bostami and Sunandan Dey. Tahsin Ahmed Rupok drafted this article and Sunandan Dey along with Bayezid Bostami critically revised the article for overall improvement of the manuscript. All authors approved the manuscript for submission.
Funding: No funding was received for conducting this study.
Availability of Data and Material: For data and material requests, please email the corresponding author.

Compliance with Ethical Standards
Con icts of interest: The authors have no con icts of interest to declare that are relevant to the content of this article.
Ethics of Approval: This research was conducted in accordance with the Biosafety, Biosecurity, and Ethical Clearance Committee of Rajshahi University, Rajshahi-6205, Bangladesh.