Can blood type determine character?
Scholars say blood type and personality have no apparent correlation.
But many Japanese believe there is a link, and such claims are often featured in magazines, books and television shows.
This year, four books linking character traits to blood types A, B, O and AB have sold a combined 5 million copies.
According to Tohan Co., Japan’s largest book distributor, “B-Gata Jibun no Setsumei Sho” (“A Book of Self-Explanation for Type-B”), sold 1.55 million copies, taking third place on a best-seller list.
What’s more, the book on type O, written by the same author, ranked fourth, while the one on type A ranked fifth and the one on AB took ninth.
“We didn’t expect to sell so many books,” said Taku Kabeya, chief editor of Bungeisha Co., the publisher. “It shows Japanese are very interested in blood types.”
The anonymous man who wrote the four books apparently has type B. Other than mentioning he is engaged in architectural design, no psychological background or profile about him is provided.
According to Kabeya, this writer’s books differ from others on the subject because he specifies various character traits according to blood type. With each description there is a box for readers to check whether his character portrayals match theirs.
“(The four books are) the antithesis of existing books that make definitive statements about a person’s character based on blood type,” he said. “(They) allow readers to pinpoint their own character.”
Blood type notions are popular topics with younger women, often in the context of relationships and possible personality conflicts.
Mayumi Hikida, 28, who lives in Fukuoka Prefecture, said discussions regarding blood types and personalities should be tongue-in-cheek and not considered a serious judge of character.
“A blood type is like a horoscope. It does not determine people’s character,” she said.
Fukuoka housewife Mari Ota, 27, who has type B, said descriptions in the best-sellers did not fit her character but they were still enjoyable reads.
“I read a lot of books that talk about the destiny of a type B person and compatibility between different blood types,” she said, adding that she was serious about blood type theory when she was a teenager.
One reason such discussions are popular here is that the blood-type distribution in Japan is more diverse than in Europe and North America, said Yasufumi Shibanai, an associate professor of sociology at Doshisha University in Kyoto.
In Japan, type A accounts for about 40 percent of the population, type O for 30 percent, type B for 20 percent, and type AB for 10 percent.
South Korea, China and Taiwan also have diverse distributions, making blood types a popular topic in those countries as well.
Shibanai said some of the credit for promoting the blood type debate belongs to the enthusiastic coverage by the Japanese media.
“If books on blood type theory become popular, the media will report about it,” Shibanai said. “People will then become interested and start observing people on the assumption that their character fits the categories portrayed in books and the media.”
He warned, however, that this could prompt people to attempt to assume the personality traits attributed to them.
“These are all interconnected and hype the theory,” Shibanai said.
Austrian biologist Karl Landsteiner first identified blood types in the early 1900s.
In 1916, a Japanese doctor, Kimata Hara, released a paper on the link between blood types and character. The theory gained ground in 1927 when Takeji Furukawa, a former professor of Ochanomizu University in Tokyo, published a series of articles titled “The Study of Temperament through Blood Type.”
In the 1970s, writer Masahiko Nomi expanded on Furukawa’s premise.
Although research from the 1910s to 1920s did not provide a conclusive link between blood type and character, many Japanese believe they are connected.
Psychologists are concerned that dwelling on blood types could lead to discrimination against people in minority blood groups.
Daisuke Nakanishi, an associate professor of psychology at Hiroshima Shudo University, points out that type B and type AB generally conjure up negative personality connotations. People with type B are often regarded as self-centered.
Nakanishi said a person’s behavior and character are the product of many variables.
“But by believing blood types can determine character, we stereotype people.”
Shibanai of Doshisha University agrees.
“Only 30 percent of the Japanese population is type B or type AB. . . . Attaching negative characteristics to a small blood group is similar to the psychological process of discriminating against minorities,” Shibanai said.
“We know in our mind that we should not discriminate against people, but we’re unconsciously doing so regarding blood types.”