When I first moved to Japan in college, every weekend meant a party and a new group of people to meet, with a standard set of questions I got asked. The logic behind “What’s your name?” was obvious, and “Where are you from?” also makes sense when you’re one of the few non-Japanese people in the room. “Do you like Japanese girls?” was another common one, based on the widely held, if not always true, theory that foreign guys like Japanese women, and vice-versa.
Those three always came first, but it wasn’t long until someone would want to know my blood type. No, my school wasn’t filled with vampires or hemophiliacs, nor hemophiliac vampires (the most tragic undead demographic). People just wanted to get a sneak peak at my personality, which is thought to be strongly connected to what runs through your veins by many people in Japan.
One man who’s not a believer, though, is Professor Kengo Nawata from Kyushu University’s Social Psychology Department, whose recently concluded research shows no correlation between personality and blood type.
Let’s start with a quick primer on blood type personality theories. In simple terms, Type As are thought to be earnest and considerate, Type Bs passionate yet self-centered, Type Os laid-back and easy-going, and Type ABs creative and mysterious.
It’s pretty easy to notice that “self-centered” sticks out as an undesirable trait in group-oriented Japan, and it’s not unusual to hear singles say “I wouldn’t want to date someone who’s Type B.” And hey, when it comes to romance, people like what they like, and don’t what they don’t. The bigger problem, though, and the one Nawata is troubled by, is companies in Japan asking about applicants’ blood types during job interviews, something the professor calls “Blood Type Harassment.”
“Sorry, your years of education, professional experience, and charitable work aren’t enough to allay our fears over your lazy, selfish blood.”
Nawata, along with a team of economic researchers, conducted a survey of more than 10,000 people in Japan and the U.S. Participants were asked for their attitudes regarding a total of 68 statements, such as “I leave fun things for later on,” and “People shouldn’t gamble.” Sawata then sifted through their responses to look for statistical discrepancies between respondents with different blood types.
The results were published in June in the journal of the Japanese Psychological Association. According to Sawata, differences between blood types were only observed for three of the 68 statements, and even then, they were minute.
“This strongly indicates that there is no connection between blood type and personality,” Sawata concluded.
Japan’s Ministry of Health, Labor, and Welfare shares Sawata’s disdain for the popular form of pseudo-science, as well as his concern over individuals’ economic prospects being inappropriately affected by their blood type. “Blood type has absolutely no relation to a person’s work abilities or aptitudes,” the organization asserted in a statement. Likewise, Osaka’s Labor Bureau has asked certain companies to stop asking job-seekers for their blood type on applications.
We suppose it might still be OK if you’re hiring workers for a blood bank, though.
So if psychologists and economists are speaking out against it, how did this whole blood type/personality thing become so prevalent? You can blame Masahiko Nomi, who wrote Understanding Affinity by Blood Type in 1971. From there, media outlets picked up his ideas, and the Japanese public imagination has never entirely let them go, despite some rather large contradictions to Nomi’s litmus/blood test of character.
For example, Al Capone’s Type O blood should have made him an easy-going guy, but history points to that label being less accurate than, say, violent mobster. And as for Type As? Well, here are two you might recognize.
▼ Considerate and sensitive
Wow, it’s like Nomi’s theories come from someone with almost no medical or psychological credentials at all! That’s not true though, at least until you remove the “almost” part. Nomi was a journalist who studied engineering in university. If being a writer without an educational background in mental health allows you to spout off on keys to a person’s psyche, my business degree and I want in on the action.
Anyone who drives a Mazda is kind and intelligent, with a great sense of humor and pleasant smell!
Some people are still unwilling to give up on Nomi’s ideas though, and usually cite two sources of anecdotal evidence. The first is that in Japan, where A is the most common blood type, being majime, earnest and responsible, is considered a virtue of the highest order. In contrast, blood type connection advocates say, the U.S. has many people who’re Type B, which is reflected in the American ideal of blazing your own trail in life.
Except, only about 11 percent of the U.S. has Type B blood, which doesn’t seem like nearly enough to be the driving force behind the country’s perceived national character. B isn’t even the most common American blood type (it’s O, and by a pretty decent margin). It’s more likely that Japan and America’s, on average, differing priorities are due to the influences of their differing historical and sociological circumstances.
Ryu’s faster fireball and Ken’s stronger dragon punch are the results of their specialized training regimens, not their respective O and B blood types
The other defense of linking blood type to personality comes from people who swear their coworker/ex/friend from high school fits Nomi’s profile exactly. While it’s hard to argue with personal experience, once again you can’t ignore the sociological factors at play here.
While some people are more interested in blood types than others, pretty much everyone in Japan is aware of the basic profiles we described above, such as type Bs being predisposed to self-centeredness. Ask yourself this, though: Do you know anyone who’s never done a single selfish thing?
Of course you don’t. Even the most considerate people occasionally give into temptation or just suffer a lapse in concentration and put themselves before others. The difference is that when Yamada, who’s Type A, finishes the last of a pitcher of beer, people think, “Eh, he must be thirsty,” or “He probably had a rough week.” But when Type B Tanaka does the same thing, he gets a different reaction.
“Haha Tanaka, you’re such a Type B!”
“Uh huh. And you’re such an -”
The human brain loves to look for patterns, and sometimes that’s a good thing. Long ago our ancestors put two and two together and realized everyone in the tribe who ate uncooked mammoth steaks that’d been lying out too long got sick and died, so maybe they should stop doing that, and our species got a little smarter and safer thanks to their powers of observation.
But sometimes, the brain goes into overdrive on its pattern hunt. When you stop and consider all of the life experiences, interpersonal relations, and soul-searching that goes into creating a person’s personality, it seems a little silly, and maybe even sad, to chalk it all up to the type of sugars attached to our red blood cells.
Sources: Yomiuri Online, American Red Cross, LiveScience, What’s My Blood Type
Insert images:Wikipeda/Everyme, Wikipedia (2)


Japan’s curious obsession with blood type and personality illustrated in one photo
It’s time for lazy calisthenics! Half-hearted exercises for those with blood type B 【Video】
What does blood type have to do with the Japan national football team?
The Osaka subway system and Dracula want to teach you about blood
The Japanese government made an idol anime, and it literally wants your blood【Video】
Pokémon and Ikea Japan cross over into each other’s worlds with collaboration events
Tokyo teahouse serves up a sakura matcha dessert you won’t find anywhere else
Tokyo turns its phone booths into free Wi-Fi hotspots, and here’s how to use them
Pokémon Centers across Japan cancel April events after stabbing in Tokyo
Eat Kuroge Wagyu beef at this Japanese restaurant in Ginza for less than 10 bucks!
Studio Ghibli unveils My Neighbour Totoro miniature house model
New Japanese menstrual product seeks to help women spot unidentified iron deficiencies
Starbucks Japan releases new My Fruit³ Frappuccino at only 34 stores around the country
Fading Tokyo – Searching for signs of the Showa era as local neighborhoods evolve[Photos]
Starbucks Japan makes hojicha black tea latte permanent item, and here’s a great way to customize it
Japan now has a special desk for people who work at home with a pet cat[Photos]
Famous Tokyo cherry blossom spot installs view-blocking screens to fight overcrowding[Video]
Uniqlo announces new T-shirts for One Piece, Naruto and more for manga publisher’s 100th birthday
Tokyo’s best museum for foreign travelers finally reopens after being closed for four years
Totoro and Calcifer become little light-up lanterns for Ghibli-style excursions or at-home decor
Pokémon lacquerware series expands for Year of the Horse with new handcrafted design[Video]
Krispy Kreme releases Super Mario doughnuts in Japan for a limited time
Picturesque Tokyo park plays host to millions of flowers and soap bubbles this spring
Tokyo subway and almost all Tokyo train lines now accepting credit card tap payments
Final Fantasy invites you to adventure in Fukushima with Fukushima Fantasy Chocobo fun[Video]
Starbucks Japan unveils new sakura cherry blossom collection for hanami season 2026
Train station platform ramen store closes its doors on half a century of history in Tokyo
Studio Ghibli releases Catbus pullback keychain that runs like the anime character
Japanese onsen egg maker from 100-yen store Daiso needs to be on your shopping list
Nine great places to see spring flowers in Japan, as chosen by travelers (with almost no sakura)
Survey asks foreign tourists what bothered them in Japan, more than half gave same answer
Japan’s human washing machines will go on sale to general public, demos to be held in Tokyo
Starbucks Japan releases new drinkware and goods for Valentine’s Day
We deeply regret going into this tunnel on our walk in the mountains of Japan
Studio Ghibli releases Kodama forest spirits from Princess Mononoke to light up your home
Starbucks Japan releases new sakura goods and drinkware for cherry blossom season 2026
Japan’s newest Shinkansen has no seats…or passengers [Video]
Major Japanese hotel chain says reservations via overseas booking sites may not be valid
Put sesame oil in your coffee? Japanese maker says it’s the best way to start your day【Taste test】
No more using real katana for tourism activities, Japan’s National Police Agency says
Health Tip: Drinking live pig’s blood may lead to worms in your brain
What type of girlfriend are you? Wait a minute, let me check your bangs
Personality test-obsessed Japan devises “Frozen” princess personality test for women
Take a trip to Japan’s Dododo Land, the most irritating place on Earth
Super blue blood moon appears over Tokyo, poses with Skytree, other landmarks for beautiful pics
Does the way you cross your arms say anything about your personality? Japan thinks so
Study of blood tests in Tokyo finds 98% as having vitamin D deficiencies
Lack of otaku blood from cancelled Comiket contributing to donation shortage in Japan
You can now get paid 5,000 yen for your poop in Japan, but only if your poop is good enough
How much is otaku blood worth? Enough to get a free anime clear file if you donate it in Japan
Criminals of Japan’s Edo Period Were Often Punished by Getting Face Tattoos
An illustrated guide to the proper way to give and receive business cards in Japan