Apparently, increasing numbers of Japanese citizens are subscribing to the theory that "blood types determine every aspect of personality, temperament and interaction with others".
Sounds suspiciously similar to astrology.
The above is an excellent working definition of pseudoscience - scientific-sounding claims sans any actual science, yet it amazingly finds popular appeal among people who ought to know better.
Despite a undeniable lack of scientific evidence proving a link between blood type and temperament, this has not stopped the Japanese population enthusiastically embracing the concept.
The descriptions of the bloodtype-derived personalities are simply absurd:
Two words: Forer effect
TYPE A – Patient, uptight, sensitive, responsible, cautious.
Famous examples: Adolf Hitler, Britney Spears, Ringo Starr
TYPE B – Individual, unconventional, optimistic, unpredictable, creative, strong
Famous examples: Paul McCartney, Jack Nicholson, Leonardo Di Caprio
TYPE O – Trendsetting, passionate, vain, self-confident, loyal.
Famous examples: The Queen, John Lennon, Liam Gallagher
TYPE AB – Sociable, popular, calm, rational, critical, indecisive
Famous examples: Marilyn Monroe, John F Kennedy, Mick Jagger
There's nothing magical about the blood type system. It's just antigens on the surface of your red blood cells, that's it. It doesn't dictate personality, it dictates immune response when receiving a blood transfusion.
The history of this incredibly gullible way of thinking makes for interesting reading:
The fad faded in the 1930s as its unscientific basis became evident. It was revived in the 1970s with a book by Masahiko Nomi, a lawyer and broadcaster with no medical background. Nomi's work was largely uncontrolled and anecdotal, and the methodology of his conclusions is unclear. Because of this he has been heavily assailed by the Japanese psychological community, although his books are phenomenally popular.
And don't get me started on the blood type diet...