Apparently, the Japanese believe that blood type is destiny. It’s their version of the zodiac:
In Japan, using blood type to predict a person’s character is as common as going to McDonald’s and ordering a teriyaki burger. The association is akin to the equally unscientific use of astrological signs by Americans to predict behavior, only more popular. It is widely believed that more than 90 percent of Japanese know their blood type.
Japanese popular culture has been saturated by blood typology for decades. Dating services use it to make matches. Employers use it to evaluate job applicants. Blood-type products — everything from soft drinks to chewing gum to condoms — have been found all over Japan.
While I have no idea how your blood type affects what kind of condom you use, I do think it’s worth pondering the effects such myths have on the cultural response to science. (And blood typology is a myth. People with Type O blood aren’t “warriors”, and having Type B antibodies doesn’t make you more “creative”.) But there is a difference between seeing fate in the stars – this is the typical Western myth: our Gods come from above – and believing that your genetic makeup determines who you are. As Theodore Bestor, a professor of Japanese studies and anthropology at Harvard University, notes:
“Japanese tend to have a fairly strong kind of inherent belief that genetics and biology really matter in terms of people’s behavior. So I think Japanese might be much more predisposed to thinking about a kind of genetic basis for personality than most Americans would.”
So even though your blood type is only marginally more predictive than your astrological sign (and that’s only because astrology has zero validity), the difference between the type of falsehood has profound cultural effects. One myth leads us to look outwards, away from ourselves and towards the great beyond. In this case, something Out There (probably God) controls our fate. On the other hand, the Japanese myth causes them to look inwards, so that they ponder the mysteries of their own insides. In both cases, our destiny is beyond our control, our lives dictated by some obscure and nonsensical factors. But at least the Japanese myth makes them look in the right direction. Shakespeare said it best: “The fault, dear Brutus, is not in our stars, But in ourselves, that we are underlings.”