Astrology has long been an integral part of many people’s lives, who live and die by their daily horoscopes. But just as common as the Western habit of someone asking to know the star sign of a new acquaintance, the Asian practice looks to a more medically-based system: blood types.

Other than the fact that you may need your blood type in the rare occasion of an emergency blood transfusion, this Asian belief— since derived from the studies of Japanese professor Furukawa Takeji in 1927— have been a necessary aspect of daily life. The cultural phenomenon that originated in Japan of reading blood types for personality traits and even matching romantic relationships with appropriate blood types is taken as seriously as Astrology, and is believed to be able to determine three of the most important aspects of modern day life: compatibility, career prospects, and diet.

This phenomenon is so ingrained in the lifestyle that there are special products offered for all the different types (from condoms to baby socks) and candidates are even asked for their blood types at job interviews and typecast into respective categories. Solidifying its position in popular culture, the Korean romantic comedy My Boyfriend is Type B follows the blood type theory, following a Type A protagonist whose love interest is an incompatible Type B. And moving to the Western hemisphere, following suit just over ten years ago, even dietician Dr. D’Adama published a New York Times' best-seller Eat Right 4 Your Type, which created a mainstream interest in the connection with blood type and diet, in which Singapore has even opened a My Blood Type Restaurant and Store earlier this year.

Following this developing trend, psychoPEDIA looks into this blood type theory and the traits associated with each:

TYPE A
The sensitive one of the bunch, Type A’s are also passionate and creative. But don’t be quick to write off Type A as the airy fairy kind, as they are perfectionists who are clever and cooperative. This enables them to be great leaders, although they can often become overhwhelmed by stress. Roles such as research and jobs that are reliant on being very meticulous such as careers in electronics will be a type A’s forte. While they are mainly calm and don’t like to take center stage, their worst traits include being extremely picky nature and sometimes overly honest. Type A’s have a tendency to have low stomach acid from birth and should be careful when having too many animal proteins in their diets. To help this, A’s should regularly include digestive enzymes that can be found in dairy. As for friendship or love matches, A’s are most compatible with other A’s and type AB’s.

TYPE B
Type B’s are hard workers, enthusiastic and relentless about getting the job done right. Despite these positive attributes, however, Type B can also be irresponsible, selfish, and arrogant. To balance their qualities a bit, though, they are also prone to empathy and always try to understand someone else’s point of view. Type B’s make excellent friends because they know when to keep in their boundaries, without being confrontational and always being flexible. Suitable jobs for B’s are: detective, artist, journalist, and psychiatrist. In terms of health, this type has a strong immune system, but is prone to diseases like Lupus, MS, and chronic fatigue. Typical B problems like hypoglycemia and imbalanced blood sugar levels can be alleviated with a good diet. Romantically, B’s are most compatible with other B’s and AB’s.

TYPE AB
With characteristics such as being cool, controlled, and rational, this rare blood type is easy to dismiss as the most favorable of them all. Under enormous pressure, Type AB is the last to crack. However, on the opposite end, Type AB can be critical, indecisive, and flaky. Apparently the most fun of the blood types, in orderly-loving Japan, they would once ostracize these types from jobs, as no one wanted to work with AB’s. They could be referred to as the lose cannon or the life of the party, depending on someone’s taste. Jobs in which Type AB’s will excel are public relations, negotiators, attornies, and company managers. While AB”s are known for having strong immunity, stress can have a strongly negative effect. Thus, special care in stress management is needed. With similar needs to A and B (just as A needs dairy in their diets), some type AB’s might also, or sometimes, have none at all, without a happy medium. Perhaps signifying this blood type as the luckiest, appropriate matches for Type AB are every other blood type, including themselves.

TYPE O
The most common blood type O’s are money hungry, relentlessly power-hungry, and ruthless and vain. However, Type O’s are also busy being agreeable, sociable, and optimistic. Using their skills of intuition, focus and self-reliance, they often get their way in situations. As O’s are mostly not in the business of making friends, purely connections, these types are often loners and leaders in occupations such as accounting, business and sales, and politics—as they are always craving to be the center of attention. Extremely confident due to well-developed physiques, O’s don’t worry much about dietary restrictions and eat whatever they want. However, blood circulation in a Type O is often sluggish, which can be corrected with regular one-hour workouts. In relationship terms, O is most compatible with other O’s and type AB.