From times immemorial, people have tried to come up with ways to make sense of another person’s personality. One way of doing so is to use astrology, where the stars you are born under supposedly influence your personality and the good and bad things happening to you throughout your life. A recent and much more scientific take on personality are the Big Five personality traits that are more or less backed up by psychological research and at least don’t try to predict what’s going to happen to you next week.
Japan however – or should I say: of course – is different. Instead of asking a person for their birth date or astrological sign, the standard question asks for blood type. Supposedly, whether you have A, B, AB, or 0 blood type tells people everything there is to know about your personality, and, of course, with which partner you are most compatible. Let’s list some of the traits upfront:
Type A: kind, compassionate, sensitive, calm, curious, loyal, idealistic, deep and committed but also obsessive, pessimistic, fastidious, stubborn, and easily stressed.
Type B: friendly, outgoing, energetic, expressive, curious, creative, imaginative, independent, and spontaneous but also wild, erratic, not forgiving, selfish, uncooperative, irresponsible, and unpredictable.
Type AB: independent, outgoing, spontaneous, energetic, fun-loving, quick, adaptable, and creative but also complicated, self-centered, irresponsible, vulnerable, indecisive, forgetful, unforgiving, and critical.
Type 0: responsible, practical, strategic, organised, determined, decisive, objective, success-oriented and logical but also jealous, rude, ruthless, insensitive, unpunctual, unpredictable, cold, self-centered and arrogant.
And as for finding the perfect partner: The individual types are best compatible with their own type and with AB, which makes AB blood types the universal donor/recipient in this case.
So, when in Japan, it is good to know your blood type to have a fun conversation topic. Obviously, most Japanese do not believe in this at all, just like most Western people don’t believe in astrology or palm reading. It’s a fun little thing to know and then we all move on with our lives because it doesn’t matter.
Obviously, we do not know who came up with astrology, that is, with the idea that the stars influence life on Earth into a personal level. Of course, when you look at the sky and see the Milky Way every night and its billions of stars, that conclusion does not appear that far-fetched.
Anyway, concerning the blood type theory, we can pin down its origins to a string of people from Japan. Aristotle already believed that personality is inherited through the blood (and may very well be, if you call it by the modern name genetics). However, it really all started in 1901 when my fellow Austrian Karl Landsteiner discovered the AB0 blood types (he received the 1930 Nobel Prize for this, by the way.)
In 1926, Rin Hirano and Tomita Yashima published a clearly racist article called “Blood Type Biologically Related” in an army medical journal. A year later, a professor at Tokyo Women’s Teacher’s School who had no medical training whatsoever, Takeji Furukawa, published a paper on temperament through blood type. The militarist government of the 1930s loved the idea and used it in an attempt to breed better soldiers and to explain the superiority of the ethnic Japanese over minorities like the Ainu or other countries’ citizens, like the Koreans and Taiwanese. This may have contributed to some of the atrocities being committed in WWII, but thankfully, the idea fell from grace during that time already.
Until, in the 1970s, Masahiko Nomi came along and breathed fresh air into the blood type personality theory, and this time, the Japanese public went with it. Of course, Nomi had no medial training either, but this did not deter him from publishing papers with what he thought was statistically significant data. His son continued in the father’s footsteps, and even established an institute for further research and publication in 2004.
Serious medical/psychological research has been done on the claims of blood type personality, and it did not find any statistically relevant correlations. What little evidence these researchers have found can be explained with the Barnum-effect, with self-fulfilling prophecies, or with similar logical fallacies.
Still, Japanese people are fond of the idea, and blood types are often mentioned in manga, anime, and video games and are even given to serious match making services. To each their own I guess – we have astrology, after all.
PS: In case you’re wondering about me and my blood type: No, it is not true at all what it says about me. I am always VERY punctual!