Can knowing your blood type provide insight into your personality and the kind of people you are most likely to associate with? For many people living inJapan or South Korea, the answer seems to be "yes". While the discovery of the ABO blood group system only goes back the work of Karl Landsteiner in 1900, this was rapidly followed by the discovery of significant ethnic differences in terms of how blood groups were distributed across the world. The overrepresentation of blood type B among Asian peoples played an early role in Nazi theories relating to racial superiority though being largely discredited by early 20th century biology. Despite the scientific racism surrounding early work into blood type, scientists linked to Japan's imperialist government drew on Nazi research to foster ideas relating to Japanese supremacy over other races during the early 1920s.
A series of research studies published during the 1920s by Takeji Furukawa of the Tokyo WomenTeacher's School had an influential role in how blood types were viewed by the Japanese public. In the first of these studies, titled, "The Study of Temperament through Blood Type", Furukawa argued that temperament was biologically determined and that various racial minorities in Japan (including Formosans and Ainu) could be distinguished from mainstream Japanese society according to blood type. Ainu, for instance, were inherently submissive since only 23.8% had Type O blood while Formosans were inherently rebellious with more than 40% having Type O blood.
Despite Furukawa's credentials being suspect and the extremely small sample sizes of his studies (as few as ten to twenty subjects in some cases), interest in his racial theories flourished until the 1930s. Furukawa's popularity eventually waned as more reputable academics pointed out the numerous flaws in his research. Still, there was an unexpected revival in 1971 when journalist Masahiko Nomi published his best-selling book Ketsueki-gata de Wakaru Aisho (Understanding Affinity by Blood Type) which reintroduced Furukawa's work to Japanese society. While not a research scientist himself, Nomi based his book on his own observations on the role that blood type played in human temperament. The popularity of his book inspired him to launch his own formal research study which he claimed involved thousands of subjects (largely recruited from acquaintances and fans of his work) as well as writing nine additional books. When Nomi died in 1981, his son took over the research and continued to promote his father's work. Despite attempts to introduce "blood type personality theory" to Western countries, the fad remains strongest in Japan and South Korea with four out of ten of the bestselling books in Japan in 2008 dealing with blood type and millions of copies being sold.
How exactly does blood type personality theory work? According to Nomi's book, the ABO blood type determines personality, temperament, and compatibility with other people. Specific blood types are characterized by representative traits that can be used to distinguish between different individuals.
- Type A Traits include earnestness, creativity, sensitivity, patience, and responsibility. Also fastidious, stubborn, tense, and shy (examples given include Adolf Hitler and Britney Spears)
- Type B Traits include passion, strength, impulsivity. Also unpredictability, selfishness, and indecision (Jack Nicholson)
- Type O Traits include amiability, optimism. Also rudeness, lack of organization, vanity, jealousy, arrogance (Elvis Presley and Queen Elizabeth II)
- Type AB Traits include coolness, rationality, adaptability. Also calculating, irresponsibility, and proneness to "split personality (Mao Zedong)
While the popularity of blood type personality theory has faded somewhat in recent years , women's magazines in many Asian countries continue to extol the virtues of blood typing (including which blood types are most romantically compatible). Japanese matchmaking services often request information on a client's blood type as part of the process of finding compatible partners. Daytime television shows offer "blood horoscopes" and even Facebook pages in many Asian countries routinely include blood type information as part of the user profile. Anime and manga authors often include information on the blood types of their different characters while video game players are allowed the option of choosing the blood type of the characters they create. Japanese entrepreneurs have been quick to cash in on the trend by offering products ranging from chewing gum to bath salts, supposedly tailored to individual blood types. Even Japanese Prime Minister Taro Aso insisted on listing his blood type on his official web page (not that it saved him from defeat in the 2009 election).
While use of blood type personality theory seems harmless enough, there is definitely a darker side. A new term, burahara, has arisen in recent years to describe the harassment that those with the "wrong" blood type may experience (burahara is derived from the Japanese words for "blood" and "harassment"). Since Type B individuals are seen as unpredictably and unreliable, employers have refused to hire qualified applicants with the "wrong" blood type. Information on blood type remains a standard question in job interviews despite efforts by Japan's Health, Welfare, and Labor Ministry to curb the practice. Children in some kindergartens are grouped according to blood type and cases of childhood bullying relating to blood type have been reported. During the 2008 Beijing Olympics, Japan's women's softball team had their training schedule adjusted according to the blood type of each member of the team (the fact that they won a gold medal did little to discourage blood-type enthusiasts).
Despite efforts by Asian psychologists to educate the public about the "sham science" surrounding blood-type personality theory, its popularity and the continuing sale of books with titles such as "Instruction Manual for People with Type B Blood" means that the fad will likely continue. At least until the next fad kicks in.
Oh, and for the record? I'm Type O (you all know what that means).