In a Nutshell
Many Japanese consider blood type the prevailing influence on a person’s nature. Blood “stereotypes” have had many consequences on society in Japan, some grim and some rather ridiculous.
The Whole Bushel
Although many will deny it, a lot of Western people take a gander at their horoscope each morning, though not many of us truly believe it determines the aspects of our personality. In Japan, this focus is not on one’s birth month, but on blood type—and they take it deadly seriously.
Blood type is determined by the antigens that cling to the surface of red blood cells, and according to numerous scientific studies, has no impact on a person’s character. Nevertheless, determining personality by blood type has been a Japanese tradition at least since World War II, when factions of the Imperial Army were organized by their types. The concept was given wider public attention when writer Masahiko Nomi published his book Understanding Affinity by Blood Type in 1971. Today, books on blood type dominate bestseller lists in Japan, selling millions of copies. The notion is particularly fashionable among young women.
It is not unusual for Japanese job applications to ask for blood type, and there are dating websites particularly for one type or another. Foods, drinks, and medications (even condoms) are “designed” to work best with specific types. Education curriculums in schools use blood type to determine the best teaching methods. In 1990, Mitsubishi built an entire team of workers from the AB type because of their “ability” to make plans. In 2011, Minister for Reconstruction Ryu Matsumoto resigned after making some tactless remarks following Japan’s devastating earthquake and tsunami. When he quit his post, he blamed his type-B blood for his brusque manner. Even video games tend to mention the blood types of their characters.
Asians show a marked diversity in blood types when compared to the West. Although there have been over 30 different types identified, approximately 70 percent of the Japanese population is type A or type O. People with rarer types can suffer from “bura-hara” or blood type discrimination. It is believed part of the reason for these stereotypes is the racial homogeneity of Japan. Because the country was closed to outsiders for so many generations, people tend to have markedly similar features, skin, hair, and eye color; blood type is one of the few things that makes people “different” from one another.