Can Blood Type Determine Personality ?


      This morning I had a discussion with my mom about whether you can/should determine someone's personality based on his/her blood type or not. I can recall many occasions in which my mom has said she finds my dad and I, both type A, "difficult to understand and hard to deal with." Everytime I hear her saying that, I have the urge to tell her that I find type O people ( my mom and my brother ) insensitive and sometimes rather "slow." I don't like people "characterizing" me using my blood type as a reference, but sometimes those traits do seem to be true. So, is blood  type really a good determinant for our personalities?
      I don't know about in the States, but in many Asian countries, especailly Japan, there is a belief that a person's blood type is predictive of his/her personality, temperament, compatibility with others, etc. Another interesting fact is that it is kind of hard to find an Asian person who doesn't know his/her blood type, but many of my American friends do now know what theirs are.
      According to this article, the four blood types (A, B, O, and AB) were discovered by an Austrian scientice named Karl Landsteiner in 1900; during that time, there were scientists trying to propagate theories of racial and gender superiority, and the "blood type theoroy" was used to "push forward their own ideas of racial supremacy" as well (for example, ethnic studies showed that a high percentage of Asian people are type B.) In 1927, Takeji Furukawa, a Japanese professor, introduced the theory in Japan with his paper called "The Study of Temperament Through Blood Type." The public bought in his ideas, and the Japanese government even commissioned a study to see if they could breed better soldiers. In one of Furukawa's studies, he compared the distribution of blood types among the Formosans from Taiwan (ME!), and the Ainu from Hokkaido. The purpose of Furukawa's studies was to "penetrate the essence of the racial traits of the Taiwanese, who recently revolted and behaved so cruelly" after Japan occupied Taiwan. Based on his study, Furukawa found that 41.2% of the Taiwanese sample had type O blood, wheares only 23.8% of the Hokkaido sample had it. Furukawa assumed that rebelliousness was genetically determined, therefore he suggested that the Japanese should increase intermarriage with the Taiwanese to reduce the number of Taiwanese with type O blood, and let Taiwanese people become more "submissive."
      Here are some common "blood type personality traits":

Type A

Type As may seem calm on the outside, but inside, you're filled with anxiety and worry. You're perfectionists and often shy and sensitive. Usually introverted, you're stable and thoughtful. You make good listeners and are sensitive to color and your surroundings. You like to be fashionable and are up on the latest trends, but never flashy or gaudy. You like romantic settings and often shun reality for fantasy worlds.

Type B
You can be very goal-oriented and often complete the ambitious tasks set before you. Outgoing and very charming, you're good at reading people and providing support. Though critical of appearance (but not your own), you aren't picky and are unlikely to dwell over the little things. Type Bs are impulsive individualists who often create their own path in life. You are very strong and optimistic.

Type O
You are the social butterflies. Often popular and self-confident, you are very creative and always seem to be the center of attention. You make a good impression on people and you're often quite attractive. Organized and determined, your stubbornness will help you reach your goals. You make good leaders.

Type AB
Not surprisingly, ABs can be quite dualistic, possessing both A and B traits. You may be shy and outgoing, and hesitant and confident. You often stand out from others, don't like labels, and are nice and easy going. You are logical and determined to do things correctly. Usually trustworthy, you like to help others. You often speak in a serious manner. Your patience, concentration, and intelligence are admirable.

What are your thoughts on blood type & personalities? Are the descripstion above accurate for you?


I am Type O and do not fit the description of a "social butterfly". I am a pro at avoiding conversation and enjoy living very far away from the "center of attention".

When searching for another prospective on this interesting topic I noticed that the overwhelming majority of the recent theories relating blood types to personality traits originated from either Japan or South Korea. I wonder why the rest of the world does not find interest in this topic? Why have more studies not been done? My only thought is that maybe the amount of subjective interpretation involved in creating these theories limits to ability of science to make any conclusions on the topic.

Interesting blog. I'm really not sure how I feel about blood type determining quality traits because I feel like there are way too many confounding variables. I am Type O and I would say that I fit many of the characteristics, but at the same time I could say the same for many of the other ones as well. I certainly think that's a problem in the study because if you place people in a category, they can often twist what is written about them to apply when really they might not. Matt also has a point, why haven't these studies been done anywhere else? There are so many theories on personality that narrowing blood type down as a contributing factor barely seems plausible. Really good blog topic though!

Wow! Very interesting article, I never thought that an individuals blood type was thought to determine certian qualities about that person. I was shocked to read that my blood type characteristic description was spot on with my personality . I have not heard about too much research or studies on this topic and will be interested to hear what will come of it.

It is interesting how there doesn't seem to be any proofs of scientific link between blood types and personalities, yet many people find the traits describe them well. I think "blood type personality traits" are kind of like "horoscope personality traits" - people collect traits from a certain blood type/horoscope and use the most common ones as that group's characteristics. I won't take those too seriously, but I'd use them as reference because it's interesting.

My blood-type description seems to fit my personality pretty well, but it seems sort of like - as you said - our horoscopes. It's pretty amazing how our horoscopes might have no relation to us whatsoever, but we can still draw some sort of relevance in it to our lives. Also, do you think this has anything to do with someone who is "type A"? I don't think when someone describes someone as "type A" or "type B" they are referring to blood type, but it might have some relation.

I've taken the A/B personality test in psych class before and found it weird too cause my blood type is A and I also have the "A personality." The descripstions for those two A's are pretty much the same. But I'm guessing that's just a coincidence cause the descriptions for a person with type B personality sound more like the ones for someone with type O blood.

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