In Japan, asking someone’s blood type isn’t just small talk—it’s a cultural quirk that shapes dating choices, hiring decisions, and even snack preferences. Inspired by a debunked 1930s theory linking blood types to personality traits, the Japanese have turned A, B, O, and AB into a national pseudoscience, blending astrology with HR departments. Forget résumés; your plasma might be your resume.
The blood type craze took off in the 1970s when a journalist compared personalities to blood groups in a bestselling book. Type A? You’re perfectionist and tense. Type B? Creative but selfish. Type O? Confident yet stubborn. AB? Unpredictable genius. These stereotypes seeped into daily life: matchmaking services tout blood type compatibility, companies draft “ideal teams” based on group dynamics (Type A for detail-oriented roles, Type O for leadership), and even energy drinks are marketed by blood type. One beer brand famously released blood-type-specific brews, because nothing says “relaxation” like a beverage tailored to your hemoglobin.
Dating apps in Japan often include blood type filters, and celebrities flaunt their types like zodiac signs. Tennis star Naomi Osaka (Type A) and actor Tom Cruise (Type O, though he’s not Japanese) have had their traits analyzed in magazines. One Tokyo woman joked, “I broke up with a guy because he was Type B. My mom said they’re flaky. Turns out, he dumped me for being too Type A.”
The “science” behind this is, of course, nonsense. No credible study supports blood type personality links, and critics compare it to believing your horoscope dictates your job skills. Yet the myth persists, fueled by media and marketing. During job hunts, some applicants still list blood types on résumés, hoping to match an employer’s “ideal” profile. One HR manager admitted, “We don’t officially ask, but if someone volunteers it, we… notice.”
The trend has downsides. Type B individuals often face unfair stereotypes—labeled as selfish or unreliable—while Type ABs are jokingly called “aliens.” In 2011, a Kyoto daycare center sparked outrage by segregating kids by blood type, claiming it improved group harmony. (Spoiler: It didn’t.)
Why does Japan cling to this? Experts blame a mix of tradition, collective identity, and the human love for categorization. Blood type is seen as unchangeable, unlike zodiac signs, making it a “fixed” trait to bond over. Plus, it’s less controversial than discussing race or religion.
Recently, younger generations have pushed back, calling the practice outdated. Yet blood type merch still thrives: there are manga guides, fortune-telling books, and even condoms labeled by compatibility. A Tokyo café once offered blood type-themed desserts—Type A cakes were meticulously decorated, Type B ones “artistically messy.”
So, next time you’re in Japan and someone asks your blood type, feel free to bluff. Unless you’re Type AB—then just lean into the “quirky genius” vibe. And remember: while your blood type won’t predict your future, it might determine if you get that promotion… or that second date. Just don’t sue anyone when your Type O boss lives up to the “stubborn” stereotype. Some cultural habits are harder to break than bad science.
