I worked with some Koreans and asking them about Fan Death is something they’ll laugh about like it’s silly but then say “but for real, you should open the door if you run your fan, just in case”. I’d imagine they feel similarly about blood types. People believe it the way they believe astrology.

Still more reasonable than basing your entire personality on the month you were born.

Younger generations are now heavily into MBTI. And I mean heavily: you won't find a person under 35 or so who doesn't know their MBTI letters.

I remember reading something about peoples personalities being vaguely related to their names which makes even less sense. Unless peoples names subtlety influence their behavior. Perhaps if these blood type ideas are so prevalent in Korea and everyone from a very young age is aware of their blood type they might have a self fulfilling prophecy.

Japanese people are the same, to the point that even anime characters have a blood type.

Well, it's definitely true to some extent, since there will 100% be some genes that contribute in some way to a person's personality that are colocated with genes responsible for blood type.

I'm pretty sure you could get statistically significant correlation and publish it (at least in psychology) if you really wanted to :)

No worries, they won't go to set up blind dates with Guadelupians.

FWIW, in trying to map normal blood types like O- or AB+ to the 47 (now 48 or 49) blood group systems, apparently that is only basically a value on the type 001 (ABO Group System) and type 004 (Rh group system). People could still have antigens that further bifurcate in the other 45+ blood group systems.

So our ABO+/- system already doesn't have information on the other 45+ systems, and this new antigen wouldn't change that high level classification.