There exists a common, popular belief in Japan, Korea, and other East Asian countries that a person's ABO blood type or ketsueki-gata (血液型?) is predictive of his or her personality, temperament, and compatibility with others, similar to how astrological signs are used in other countries throughout the world.
People throughout history have sought to categorize themselves and each other. For example, Hippocrates (406-377?B.C.) and Aristotle (384-322B.C.) attempted to classify personalities according to bodily humors and blood. According to social scientists, this recurring desire stems from an urge to define the self and others in specific social and cultural roles. In 1930, Tokeji Furukawa contributed to the classification efforts by choosing blood as a physiological classification characteristic; Furukawa’s assertions caused an impact that would shape the next eighty years of popular Japanese culture.
While blood typecasting hasn't hit Canada, we certainly have our own ways of grouping people, from western and Chinese astrology to the Myers-Briggs Type Inventory to the theory of Type A and Type B personalities. We've got numbers, too, like the Enneagram, which was promoted in a book called Getting Your Boss's Number. They're all good fun, unless they're used for discrimination--for which our DNA might pose the biggest threat of all.
Blood type personality analysis appears regularly in Japanese women's magazines. Last year, more than 50 television shows dwelled on the subject. Matchmaking agencies offer blood type compatibility tests.
It is considered perfectly acceptable to ask a person's blood type and make it public. Blood types are listed in Japan's "Who's Who in Politics and Government."
Children at some kindergartens are divided up by blood type, and the women's softball team that won gold at the Beijing Olympics used the theory to customize each player's training.
Not all see the craze as harmless fun, and the Japanese now have a term, "bura-hara," meaning blood-type harassment.
And, despite repeated warnings, many employers continue to ask blood types at job interviews, said Junichi Wadayama, an official at the Health, Welfare and Labor Ministry.
A person's blood type is determined by what kind of antigen, a type of protein, he has on the surface of his red blood cells. If a person has an A antigen, his blood is type A; if he has a B antigen, he's type B. People with both are type AB, and those with neither are type O. The most common type is O, followed by A, B and AB.
There is not one molecule of solid scientific evidence that blood type is related to character. Scientists say blood type is about as relevant to personality as hair color is to snorkeling ability.
The theory's popularity aside, what do blood types reveal about character?
Little or nothing, according to scientists. A great deal, in the opinion of many other Japanese.
"Most of us view it with a snicker," says Tadao Miyamoto, a psychiatry professor at Jichi Medical School, north of Tokyo. "Personally, I don't believe in it at all.
"Scientifically speaking, it is not an issue. I don't think there is any scholarly research on it. There are scores of more pressing topics for research."
In Japan, the trendiest taxonomy involves a "type" with scientific legitimacy - blood type. According to Joji Sakurai, a writer for the Associated Press, men and women in Japanese bars get to know each other by asking for one another's blood type.
In Japanese lore, which medical scientists tend to dismiss, "Type A blood is thought to produce nitpickers, while B people are seen as free-wheeling and O's as driven." In some cases, according to the AP story, individuals are discriminated against in the workplace because they have the "wrong" blood type.
If you're an A, you probably get uptight when the silverware's out of place or if trains run off schedule. Attention to detail combined with a desire to please others are other hallmarks.
Hear a single, raucous voice booming across the room at a party? You can bet it came from one of those pushy B's.
O's are said to be highly motivated and intent on controlling group situations.
AB's are a bundle of contradictions but are also believed to produce original ideas.
The idea first came about in the 1920's and is still publicly used today - who could forget Japan's minister Ryu Matsumoto blaming his blood type on his abrasive behaviour?
According to experts, such as Dr. Peter D'Adamo, author of Eat Right For Your Type, "Your blood is the key to unlocking the secrets to your biochemical individuality."
Ryo Matsumoto, who was appointed only last week, was widely criticized after publicly scolding a governor, refusing to shake his hand and threatening to withhold aid to badly hit communities.
Offering his resignation, the minister blamed his indelicate behaviour on the fact he is blood type B, tapping into the popular Japanese belief that blood types dictate personality traits.