Here’s something that’s been on my mind for years, and probably on other Readers’ minds too: The emphasis on blood in Japan in determining one’s status in society.
The BBC below talks about the hegemony of discourse in Japan linking personality traits to blood types. Most of the developed world with any social science training has debunked this. There is of course other quackery of the same ilk (horoscopes/palmistry etc.), but they are hardly taken seriously (they don’t matter in, for example, job interviews). But “blood”-based conceits encourage much more dangerous habits. As noted below, they have historical connections with eugenics, Master-Race theories and Social Darwinism (i.e. that people can be sorted into personality “types” based upon birth-determined genotypical markers) which, in extreme cases, have led to pogroms and genocide.
Yet in Japan, blood-based theories of social behavior hold significant sway. In my opinion (based upon my current research), a conceit with “blood” not only legitimizes a lot of bad science (both physical and social), but also converts a lot of latent racializing tendencies into “old-school racism” (I say “old school” because most social scientists nowadays acknowledge that racism is a social construct, not a biological one). In some cases, for example, one has to be “pure-blooded” in order to be, for example, a “real” Japanese. Thus it doesn’t just allegedly determine personality — it determines one’s legal standing in society. More on that from me some other time.
In any case, in society such as Japan’s that has this amount of weight put on hierarchy, having a quack science like this (so normalized that people can profit handsomely from it) avails people with poor analytical skills of one more factor to “sort, categorize, typify, and even stigmatize” people for things that are simply not their fault. It’s one more way of taking the individual out of the equation for personal behavior.
Simply put, this pseudoscience fosters horrendously bad habits. For in Japan, once the “blood type” equation is expanded beyond the allegedly “uniform and homogeneous society” trope, people become more susceptible to engaging in racial profiling towards “foreigners” — once the invisible genetic markers get expressed as visible phenotypical ones.
In sum, dumb ideas with common currency dumb down an entire society. And personality typing by blood is one of the dumbest.