What’s with Japanese stuff always listing people’s blood types

Seems like an Asian thing. My wife grew up in asia and kept asking me what my blood type was early on. She was really confused when I kept telling her I don’t know we don’t really emphasize that in America

Well it’s a form of pseudoscience I think with like the weight loss diets by blood type.

That said there have been some studies linking certain disease outcomes or overall health with certain blood types that may be statistically true.

Not sure if or when it started in Japan.

There is this popular Asian myth that personality has something to do with blood type - so much so that

“…no less than two-thirds of people in several East Asian countries and areas, such as Japan, Korea, and Taiwan, believe in the association between blood types and personality…Many people in Japan and Korea have been discriminated against because of their blood type. Employers ask blood types during interviews despite the warnings they have been given. Children at schools have been split up according to their blood type. The national softball team has customized training to fit each player’s blood type. Companies have given work assignments according to their employee’s blood type.” (Wikipedia)


There’s a theory of marriage compatibility based on blood types.

I guess it’s the Japanese equivalent of astrological signs, but a large percentage of the population seems to take it seriously.

A good article written for visitors to Japan and people who want to understand Japanese culture:

Do you know what blood type you are? What about the blood type of everyone in your family?

I do, and I even know the blood type, or ketsuekigata, of all my friends, too. And I’m not alone. According to a 2016 survey of 3,355 Japanese people, 99% knew their blood type.

Wow! But why all the blood knowledge?

In Japan, blood types are considered an important indicator of a person’s personality. It’s known as the “Japanese Blood Type Personality Theory.” Though this may seem far-fetched, a lot of people believe in it. In fact, the aforementioned survey shows 29% of males and 45% of females believe.

This is only a Japanese (and possibly Korean) thing. Please don’t lump all of Asia with foibles of one country.

Errr…it is a bit more than those two. Taiwan has a sizable number of people who ascribe to it; some Chinese do too.

Therefore all of Asia believes the foolishness? Does India? Does Malaysia? Does Tajikistan?

A lot of Americans use “Asian” to mean East Asian (Japanese, Chinese, Korean) or at most East and Southeast Asian.

I remember the confusion of many of my coworkers when we had a presentational of Indian cuisine and dance as the centerpiece of our Asian American and Pacific Islander Heritage Month observations. These included co-workers of Chinese, Korean and Vietnamese descent. Heck, my wife who is Chinese-American doesn’t intend to include me (Indian American) when she says “Asians”!

In fact when I joined the “Asian American” professional organization for my specialty in 2009, I was the only South Asian in the local chapter (several hundred strong), and seem to have puzzled and even annoyed many members. Now there are a few South Asians but still no one of Southwest Asian heritage that I know of. And almost all of the members from Malaysia and Indonesia identify as “Chinese from Malaysia” or “Chinese from Indonesia”

In fact I know of Tajik-, Turkish- and Lebanese-American colleagues who insist that they are NOT Asian-American.

Yeah, I think it is partly discriminatory. Small European countries are known by their names like Danish or Belgian … But when it comes to Asia, white Americans have clubbed all cultures and countries into one group whether they identify as such or not.

People tell me Asian jokes all the time! Asian drivers, Asian parents, Asian shopkeepers.

Never mind that I identify as Asian, am married to a Chinese person. They also must think I’m too stupid to realize that if you’re making racist “jokes” about [east] Asian, Jewish or Black people around me, that behind my back you’re making similar remarks about me.

You said “only a Japanese (and possibly Korean) thing.” I was pointing out that it’s more than just those two.

This book came out in 1988 and introduced the concept to the mass American audience. I don’t know how early it was in Japan, but since the author was the founder of Japan’s ABO Society I’d guess pretty early and important.

Errr…it’s condension I was responding to.

No, it is pretty common to see something described as “European”. Example:

Europeans cannot be blamed for blood types and horoscopes, but they have phrenology and haruspicy to their credit.

ETA though it does seem that ABO blood types and antigens were discovered by Karl Landsteiner working at the University of Vienna.

Europe may have haruspicy, but Japan has spicy Haru.