This article on Epainassist.com has been reviewed by a medical professional, as well as checked for facts, to assure the readers the best possible accuracy.

We follow a strict editorial policy and we have a zero-tolerance policy regarding any level of plagiarism. Our articles are resourced from reputable online pages. This article may contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

The feedback link “Was this Article Helpful” on this page can be used to report content that is not accurate, up-to-date or questionable in any manner.

This article does not provide medical advice.


Can Your Blood Type Define Your Personality?

Personality typecasting has been a popular and much-debated topic over the years. People categorize personalities based on various factors, including zodiac signs, favorite colors, by answering questionnaires and many other similar things. One popular personality typing system that has become quite popular in recent times is one based on your blood group. Well, as surprising as that sounds, it is indeed true that there is a popular personality typing system out there that is entirely based on your blood type. Read on to find out if your blood type can define your personality.

Origin of the Blood Type Personality Theory

The concept of personality typing is not new, especially the idea of your blood type being linked with certain personality traits. The origin of blood type and their effect on personalities have their origin in Japanese culture, where blood type has even been used as the basis for choosing one’s life partner and many other predictions.(12)

In fact, towards the end of the 1920s, Tokeji Furukawa, a research psychologist, further fueled these cultural beliefs with the publishing of his research paper titled ‘A Study of Temperament and Blood Groups.’(3) For this study, Furukawa had asked the participants to look at their own personalities and answer an 11-question survey. Furukawa found that the answers to the 11 questions seemed to correspond to the subjects’ blood types. While the study was not a very big one, but having 188 adult participants aged between 27 and 70 years, as well as 425 participants who were between the ages of 16 to 21, the study still holds some value.

Furukawa’s research made use of the personality type categories that were first expressed by the ancient Greek physician Hippocrates. These included:

  • Sanguine
  • Choleric
  • Phlegmatic
  • Melancholic

According to the results found in Furukawa’s survey, it seemed like:

  • People with A blood types were found to be melancholic, self-reliant, and deep thinkers.
  • People with B blood types were found to be sanguine, socially active, and outgoing.
  • People with O blood types were found to be phlegmatic, peaceful, or relaxed.

When you look at the grand picture, of course, this evidence does not seem very reliable, but it nevertheless took hold of the people of Japan and South Korea. Today, this system is known as katsueki-gata, and it is based on Furukawa’s theory that your blood type has an influence on your personality and behavior. Furukawa died within 13 years of publishing his initial research on katsueki-gata, and he could not provide any further scientific evidence to establish his theory more firmly.

However, in the 1970s, a Japanese journalist named Masahiko Nomi attempted to explore Furukawa’s research further and take it a step further with the publishing of a book titled ‘Understanding Affinity by Blood Type’ in 1971. The book immediately became a clear bestseller in Japan. In his book, Nomi theorized that almost a quarter of a person’s personality and behaviors are due to their blood type. This was not Nomi’s only book on the subject, and he went on to write several more books offering advice and predictions on how to live based on your blood type.(45)

Is There Any Scientific Proof of Blood Type Influencing Personality Traits?

Though there has been a large amount of interest in the concept of katsueki-gata, there is a lack of scientific evidence to confirm this association.(67)

There has been some research that indicated that there are certain blood types that are believed to be more resistant to some types of health conditions.(8) There is another school of thought that believes that certain blood types tend to do better if they follow a blood-type-specific diet.(9)

However, to date, no research has shown any relationship between blood type and personality, especially within a large study group.

It is important to understand that what we refer to as a person’s blood type is just a way to describe the antigens present on the surface of the red blood cells. Everyone is familiar with the ABO blood typing system. According to this, there are four major blood types, which include:(10)

  • A, which has the A antigen present on the surface of the red blood cells
  • B, which has the B antigen present on the surface of the red blood cells
  • AB, which means that both A and B antigens are present
  • O, which has no antigen present on the surface

Knowing your blood type is important for many medical procedures, especially when it comes to performing blood transfusions safely. Since the discovery of the ABO blood typing system in 1901, uncountable lives have been saved just by having information about their blood type.(111213)

Prevalence of Katsueki-Gata

From the 2010s to even today, there have been many books on the topic of katsueki-gata that continue to remain on top of all bestseller lists in Japan and many other countries. There is no doubt that the topic of blood types and their link to personality traits remains compelling, even if there is no evidence to back it up. Many even wonder why this is so.

Personality typing based on something like your blood type or your zodiac sign is a very appealing concept to people because they are based on something that remains unchangeable about you. As noted by Furukawa in his original paper, there is really no objective method by which a person’s temperament can be measured or judged. This is why he hoped that blood typing if it could be proven scientifically, would offer one such objective method for people to measure their personality traits.

Every person has a certain idea in their mind about who they are and what is the most important or appealing thing about them. However, one of the most frustrating and restrictive things about human nature is that it is impossible for a person to know if their own perception of themselves is the same as what other people see them as. This is what has made the concept of personality typing so appealing all over the world because it helps answer a few simple questions that we believe can help reveal a deeper truth about ourselves that we are otherwise not able to see.

At the same time, katsueki-gata claims to offer an approach to how one should approach romantic, professional, and personal relationships and provides an explanation for all the hardships one faces in life.

Personality typing of any type is just a suggestion that your social behaviors are majorly predetermined by factors you cannot control, apart from also suggesting that your interactions with other personality types can be looked at like a scientific problem that has a definite outcome.

It is natural for anyone to want to find rules of order that can help govern the way each one of us understands relationships. However, as long as we understand that there are restrictions to these systems, there is no harm in exploring them.


There is, at present, no scientific evidence to show that there is any relationship between your blood type and personality. It is essential to keep in mind that there are only four blood types, and your personality is layered and complicated. Each person’s personality is also completely unique. However, there is no harm in wondering whether certain personality traits could be connected to certain blood types. Personality typing is a fun way of trying to understand oneself better, and it can even give you a better perspective to see yourself as compared to other people.


  1. Robertson, J., 2012. Hemato-nationalism: the past, present, and future of “Japanese blood”. Medical Anthropology, 31(2), pp.93-112.
  2. Marriage, E., 2008. 21 Biopower: Blood. A Companion to the Anthropology of Japan, 9, p.405.
  3. Furukawa, T., 1930. A study of temperament and blood-groups. The Journal of Social Psychology, 1(4), pp.494-509.
  4. Blood type and its major traits of personality (NOMI) (no date). Available at: https://www.researchgate.net/figure/Blood-Type-and-Its-Major-Traits-of-Personality-Nomi_tbl2_350588165 (Accessed: December 23, 2022).
  5. Nakamine, K. (2017) Japanese blood types: And what they say about your personality, Tofugu. Tofugu. Available at: https://www.tofugu.com/japan/japanese-blood-type/ (Accessed: December 23, 2022).
  6. Tsuchimine, S., Saruwatari, J., Kaneda, A. and Yasui-Furukori, N., 2015. ABO blood type and personality traits in healthy Japanese subjects. PloS one, 10(5), p.e0126983.
  7. Mao, X., Xu, M., Mu, S., Ma, Y. and He, M., 1991. Study on relationship between human ABO blood groups and type A behavior pattern. Hua xi yi ke da xue xue bao= Journal of West China University of Medical Sciences= Huaxi Yike Daxue Xuebao, 22(1), pp.93-96.
  8. D FARHUD, D. and Yeganeh, M.Z., 2013. A brief history of human blood groups. Iranian journal of public health, 42(1), p.1.
  9. Wang, J., García-Bailo, B., Nielsen, D.E. and El-Sohemy, A., 2014. ABO genotype,‘blood-type’diet and cardiometabolic risk factors. PloS one, 9(1), p.e84749.
  10. Dean, L., 2005. The ABO blood group. In Blood Groups and Red Cell Antigens [Internet]. National Center for Biotechnology Information (US).
  11. Nawata, K., 2014. No relationship between blood type and personality: Evidence from large-scale surveys in Japan and the US. Shinrigaku Kenkyu: The Japanese Journal of Psychology, 85(2), pp.148-156.
  12. Tsuchimine, S., Saruwatari, J., Kaneda, A. and Yasui-Furukori, N., 2015. ABO blood type and personality traits in healthy Japanese subjects. PloS one, 10(5), p.e0126983.
  13. Kanazawa, M., 2021. A pilot study using AI for psychology: ABO blood type and personality traits. American Journal of Intelligent Systems, 11(1), pp.1-7.
Team PainAssist
Team PainAssist
Written, Edited or Reviewed By: Team PainAssist, Pain Assist Inc. This article does not provide medical advice. See disclaimer
Last Modified On:January 3, 2023

Recent Posts

Related Posts