Are you hot headed? Cool and calm? Your personality might be determined by the type of red stuff flowing through your veins.

By Yumi Nakata Aug 19, 2014 2 min read

Japanese people love to ask the question: “What’s your blood type?” Is that because they are concerned about your health? Are they worried that you might need a blood transfusion? No! It is because many of them believe that blood type determines your personality.

Growing up in Japan, I had never questioned the theory of blood type because everyone including teachers, parents, friends and even potential employers have asked my blood type. Certain blood types are more favourable and some of my friends have even lied to employers about their blood type to try and secure the job.

There is no scientific evidence to back up the blood type personality theory, but blood type matters to many Japanese people

My blood type is AB, which is the least common in Japan and we are the most discriminated against in Japan. We are odd, eccentric, unpredictable and we are not worried what other people think of us. I don’t remember how many times my classmates asked my blood type and many of them said to me: “I can see that you are AB.”

It may be a surprise to many westerners but many dating agencies in Japan encourage subscribers to list their blood type on their online profiles. I don’t think I would be very comfortable with this idea because my blood type may drive many potential partners away!

What is that supposed to mean? This infographic shows a fascinating history of this practice that pervades Japanese culture.

Do I believe in blood type theory of personality now? I am not quite sure because it seems to work really well among Japanese people. I am a typical AB and my other friends with blood type AB also have unique personalities and they are outcasts. My friend and one of my sisters with blood type B are pretty assertive and I often find myself trying not to take what they say personally. Most people with blood type O that I know are pretty laid back.

In the U.S., people are often categorized into different racial groups but because Japan is ethnically and culturally homogenous we use blood types to evaluate and categorize each others.

I wish more studies on this subject will be done and hopefully the reputation of Blood Type AB will improve in the future!