Guides

Everything about blood types

The culture behind blood type personality, and the real science of blood groups.

• 🔬 Is Blood Type Personality Real? What the Research SaysBlood type personality is hugely popular in Japan and Korea, but large studies find no meaningful link between ABO blood group and personality. Here is the evidence, and why the idea still feels true.
• 🇰🇷 Blood Type Personality in Korea: From "Type B Boyfriends" to K-pop ProfilesWhy South Koreans talk about blood types, the famous "type B man" stereotype, how K-pop idols list their blood type, and how the trend has shifted toward MBTI.
• 🇯🇵 Ketsueki-gata: The History of Blood Type Personality in JapanHow blood type personality theory (ketsueki-gata) started with Takeji Furukawa in 1927, returned through Masahiko Nomi's books in the 1970s, and became part of everyday life in Japan.
• 🌍 Blood Type Distribution by Country (A, B, O, AB and Rh-)How common each blood type is in the US, UK, Korea, Japan, India and worldwide, including Rh-negative rates, with notes on why the numbers differ.
• 💎 What Is the Rarest Blood Type? (From AB− to Rh-null)AB negative is the rarest of the eight common blood types, but true rarities like Rh-null and the Bombay phenotype are far rarer. Here is how rare each one is.
• 🩸 Blood Donation Compatibility Chart: Who Can Give to Whom?A clear chart of red blood cell and plasma compatibility for all eight blood types, plus why O negative is the universal donor and AB positive the universal recipient.
• ➕ Rh Negative Blood Explained: What the + and − MeanWhat the Rh factor is, how common Rh-negative blood is around the world, how it is inherited, and why it matters in pregnancy.
• 🔍 How to Find Out Your Blood Type (5 Easy Ways)Don't know your blood type? Here are five ways to find out, from donating blood to home test kits, and why many people in Korea and Japan already know theirs.