Hypothesis (November 20, 1997)

Why does the ABO blood type cause the difference of personality?

Kumiko TAKEUCHI's book "Chiisana akuma no senaka no kubomi" ('small devil's hollow of back' ) propose some hypothesis from infection.

  1. The strength order of infection: Type O, then B, then A, then AB.
  2. To prevent an infection, one does not get in touch with people, and which is "unsociable" personality.
  3. But to conserve one's gene, one must be "sociable" (especially opposite sex people!).
  4. Accordingly, infection-strongest Type O is most "sociable" and thus Type AB is most "unsociable".

In fact, the condition of 4. is materialized by natural selection. Also, not all people becomes Type O, because Type O is not strong to all infections. As she checked the infection and blood type distribution of all around the world, blood types that are strong to area-unique infection are prevailing.

Furthermore, HLA (Human Leukocyte Antigen), a type of white blood corpuscle, seems more likely to be related to personality, says Kumiko TAKEUCHI.

Let's try to inspect the above hypothesis!

The following is my original inspection. Although this is the combination of NOMI's books and TAKEUCHI's.

According to Mr. NOMI, Type-O and Type-B people like to touch and to be touched by other people. But Type-A and Type-AB people are not. It agrees with my observation. You may have understand already. People was infected by touches of other people (who are already infected). Infection-weak Type-A and Type-AB people dislike to be touched by others, while infection-strong Type-O and Type-B people are like to be touched. Conglatulations!

Numerical Proofs (November 20, 1997)

Let's proof the order of group-dependence, which is O=A>B>AB (Valid only in Japan?).

Preliminary trial: questionnaire

The data (table 18, pp.71) from "Shin ketsueki-gata ningen-gaku" (New blood type humanics) published in 1978. Results of a questionnaire to first-class Japanese athletes (exact dates were not specified). The ratios of athletes who choose "Do the best for Japan" in the international game.

Blood type Number of persons Ratio
O 58 people 13.8%
A 73 people 13.7%
B 51 people 9.8%
AB 22 people 0.0%

It is the order of O=A>B>AB as expected. To my surprise, the ratio of Type AB is 0! Type-AB people doesn't identify themselves with their country -- Japan.

The Secondary trial: questionnaire

The next data from the same book (table 24, pp.211). The question is "Which do you feel best when eating with people?" The ratios of people who choose "Eat alone". Exact dates were not specified.

Blood type Number of persons Ratio
O 636 people 20.1%
A 739 people 19.6%
B 600 people 23.2%
AB 428 people 27.1%

It is the order of O=A<B<AB, too, as expected. It is clear that Type-AB people like to be alone.

The Third trial: Raymond B. Cattell's Study

Famous psychologist, Raymond B. Cattell's Study shows the clear relation of blood types to personality traits. Click here!

Results of The ABO System

Australians are the same trend for the most part, although a dangerous rate is a little bit high, because there are few Type-AB people.

The last trial: Japanese psychologist

The same trend showed by Japanese psychologists. Surprisingly, probabilty is below 0.1%. The ratio of the person that chose "Esteem rule, custom and order" (Taketoshi TAKUMA and Yutaka MATSUI, 1985, About blood type stereotype, Jinbungakuho,172,15-30.).

Blood type Number of persons Ratio
O 29.7% 57.7%
A 36.7% 54.7%
B 22.5% 50.7%
AB 11.1% 41.2%
Total 613 people in all -

Even, this is the order of O=A>B>AB as expected.

The Gene and Personality (September 19, 1998)

Dean Hamer, Ph. D., is Chief of Gene Structure and Regulation at the National Cancer Institute's Laboratory of Biochemistry.  Coauthor Peter Copeland is an award winning journalist.
According to the authors, certain genes affect dopamine or serotonin to make difference of personality traits.  Some researchers say that certain HLA types might affect neuronal post-synaptic membrane sensitivity to central neurotransmitters -- such as dopamine -- because both chemical structure is much the same.  So, ABO blood type might affect dopamine and/or serotonin to make difference of personality traits if structure is much the same ...

Living with Our Genes -- Why They Matter More Than You Think --(1998) by Dean Hamer, et. al. (from pp. 76-80)

harmer.jpg (10677 バイト)


     Murphy and Lesch's persistence had paid off. They'd found an inherited variation in DNA that clearly affected serotonin transport. Here was a little button effectively controlling levels of serotonin in the brain. Now the key question was, What did this "genetic Prozac" do in human beings? What effect did it have on temperament?
     Murphy and Lesch were pretty sure what the gene was not. They doubted it was an on-off switch for some mental illness; it was just too common. If it were a controlling factor in major depression, for example, that would mean at least one-third of the entire population should be feeling terrible. They figured the variation played a role in a more normal-meaning more common-variation in personality. The problem was that most of their research subjects were uncommon: they were psychiatric patients with serious problems. The researchers needed DNA samples and personality profiles on a broad range of healthy people. They called me.
     Murphy and I had collaborated previously looking for the novelty-seeking gene. He knew I had exactly the material he needed, and within a few weeks, postdoctoral fellows Sue Sabol in my lab and Dietmar Bengel in Murphy's lab had genotyped 505 individuals for the DNA region just upstream from the serotonin transporter. They looked at every person for whom we had personality scores -- college students from local campuses; gay men from our studies of sexuality and AIDS; brothers and sisters, fathers and mothers; young and old; white, black, yellow, and brown; male and female. Once all the bench work was done on the DNA, it was a simple matter to match the data with the personality test scores.
     We held our breath as the first results rolled down the computer screen. Given all the various functions ascribed to serotonin -- from anxiety to depression to aggression, not to mention eating and drinking, cognition, and sex -- it was an open question whether we'd see anything specific or indeed anything at all. Maybe serotonin was responsible for so much that it wouldn't be linked with any of the narrow traits we were looking for. On the computer screen, we were search ing for stars. As the statistical results were churned out, two stars (**) indicated that a result was significant at the p <0.01 level, which meant less than a 1 percent chance of being a fluke.
     The earliest results were based on a standard personality test that measures five major traits. First we ran the DNA data against the factor for conscientiousness, which means dependability and organization. If the people who scored high or low for conscientiousness shared anything in common about this bit of DNA, the computer would catch it and mark it with a star. The first results were negative; no stars, no correlation. Next we ran the data for the trait of openness; nothing. I crossed my fingers as we punched in the third factor, extroversion. The numbers ran, the results popped onto the screen. No stars.
     The first hit came with agreeableness. That made sense because one aspect of agreeableness (or the lack of it) is aggression, a trait ascribed to serotonin. The correlation was weak, though, only one star. It wouldn't be much of a link, but it was encouraging. The computer ground on. The fifth and final factor was neuroticism, a measure of anxiety, emotional stability, and reactivity to stress. These were exactly the traits that should be involved if we really were looking at a genetic Prozac. If we didn't get a hit here, we weren't going to find it anywhere.
     I watched the screen. New numbers popped into view. My face lit up in a big smile. Not one star. Not two stars. But three stars -- less than 1 chance out of 500 that the correlation was just by chance. And right bang on where we expected it.
     This was great news, but it was only a beginning.
     Next we started looking at the data from every possible angle. Maybe there was something obvious we were missing, or perhaps the way we had collected the subjects had biased the sample. First we split the subjects into those who'd been recruited through the National Institute of Mental Health and the National Cancer Institute. There was no difference: both groups showed the same significant correlation to neuroticism but not to the other factors. Next we checked females versus males, and straights versus gays; the neuroticism factor continued to shine through. We corrected the data for age, ethnic group, education and income; no matter how we crunched the numbers, the result stayed the same.
     I still wasn't convinced. It was possible the results were just some sort of coincidence based on the five-factor structure of the personality test. The questions we asked people about their personalities or how we categorized the answers could have led us in the wrong direction.
     Fortunately our subjects had been given not one but two different personality tests. Since there is much disagree ment about how to describe and measure personality, we wanted to use as many different yardsticks as possible. The second test is called the 16 Personality Factor inventory, developed by the pioneering American psychologist Raymond Catell in the 1940s. The 16PF divides personality into five factors formed from 16 core traits.
     When we matched the DNA data on our subjects with Catell's traits, a star appeared by only one of the five superfactors: anxiety. The correlation was right where we expected it to be, confirming that we really had found a link between the DNA region and a basic personality trait.
     The final analysis was to look at Cloninger's predictions. He had theorized that serotnin would be involved in harm avoidance, and now we had a chance to test the theory. He was right. We found a significant correlation between this DNA region and the trait he called harm avoidance, which we could estimate by mathematically rearranging the questions from the five-factor test. There was no correlation for any of the other traits he identified. This was the second confirmation of Cloninger's theory. He also had guessed right that dopamine was linked to novelty seeking, and now he was proved right that serotonin was linked to harm avoidance. His model of personality was starting to look pretty good indeed.
     There was one intriguing twist to the story. The people with the highest level of anxiety-related traits had the short version of the gene promoter. This meant that where the serotonin transporter was least efficient, people had the most anxiety. This was the opposite of the Eli Lilly explanation for how serotonin works; it should have been the lowered serotonin transporter levels that were associated with decreased harm avoidance. Our results were more consistent with the "classical" model that serotonin causes rather than alleviates anxiety, depression, and other elements of harm avoidance.
     It's difficult to draw any firm conclusion yet about the direction of serotonin action, however, because it's possible that a lifelong decrease in serotonin transporter gene expression actually decreases serotonin signaling through a feed back or compensatory mechanism. What's really needed is a direct way to measure serotonin signaling in the living brain -- but that's not available yet.
     Our study not only confirmed the connection between the serotonin transporter and harm avoidance, but it also provided the first conclusive evidence that the multiple facets harm avoidance are connected at the level of the genes. That's because the differences in the DNA correlated equally well with several different aspects of harm avoidance: anxiety, depression, hostility, pessimism, and fatigability. Thus the results were a satisfying confirmation of the claim that a single set of genes -- in this case just one gene -- can influence distinct traits that are obvious in real people.

Lesch, Klaus-Peter, Dietmar Bengel, Armin Heils, Sue Z. Sabol, Bejamin D. Greenberg, Susanne Petri, Jonathan Benjamin, Clemens R. Muller, Dean H. Hamer, and Dennis L. Murphy. "Association of Anxiety Related Traits with a Polymorphism in the Serotonin Transporter Gene Regulatory Region Science 274,1527-31 1996.

Underlined sentences are authors' conclusions.  After all, dopamin is connected to novelty-seeking and seretonin connected to harm avoidance. Might Type B affect dopamine and Type A affect seretonin?   That can explain the difference of personality by blood type ...

Biochemical Explanation? Part 1 (September 19, 1998)

The followings are the structure of dopamine and blood type substances:

dopamine.gif (2144 バイト)

galactose.gif (2619 バイト)

acetyl.gif (3119 バイト)

D-galactose - N-Acetylglucosamine - D-galactose - N-acetylgalactosamine
N-acetylgalactosamine - D-galactose - N-Acetylglucosamine - D-galactose - N-acetylgalactosamine
D-galactose - D-galactose - N-Acetylglucosamine - D-galactose - N-acetylgalactosamine

Interestingly enough, the structure of dopamine and blood type substances resemble each other.  They are some kind of amines.  This may explain the difference of personality by blood type ...
Neural impulses are transmitted by Na and/or K ions.  So amines (alkali NH base) of blood type substances might affect neural impulse transmission.  Or blood type substance might affect receptor and/or neurotransmitter, directly ...

Biochemical Explanation? Part 2 (September 19, 1998)

The followings are my "peculiar" hypothesis.

Let's calculate "effect" of amines.   Terminal molecules affect most, usually, so add 1 point for yellow ones and 0.5 point for white ones.  Then calculate "amine rate" that is amine points divided by total points. Type O's amine rate is 0.20, Type A's is 0.43 and Type B's is 0.14.  So, A>O>B in order.

D-galactose - N-Acetylglucosamine - D-galactose - N-acetylgalactosamine ---
N-acetylgalactosamine - D-galactose - N-Acetylglucosamine - D-galactose - N-acetylgalactosamine ---
D-galactose - D-galactose - N-Acetylglucosamine - D-galactose - N-acetylgalactosamine ---

Amines of blood type substaces may disturb functions of neurotransmitters.  So ...

According to "Living with Our Genes", more dopamine causes novelty seeking and less serotonin transporters causes harm avoidance.   This may explain the traits that Type B is curious and Type A is caucious ...
Ms. Kumiko Takeuchi says, in her book "Chiisana Akuma no Senaka no Kubomi", that every blood type has Type O substace. So ...

The less number of blood type substances is, the more stable transmission of neurotransmitterstraits might be ... So, Type O is most stable, then Type B and A, then Type AB.  Don't you think this might explain blood type traits well?

Anyway, Type AB, my blood type, is least stable :-<.

Structure of Neurotransmitters

adore2.gif (2820 バイト)

norad2.gif (2989 バイト)

dopa2.gif (2393 バイト)

sero2.gif (2638 バイト)

from Heibonsha "Sekai Dai Hyakka Jiten [World Encyclopedia]" (1988 version)

Biochemical Explanation? Part 3 (March 18, 2007)

Another article by Dr. T. Abo

   In addition, there is a study to understand activities of the sympathetic / parasympathetic nerve by examining the ratio of polymorph and lymphocytes of white blood corpuscles.

   According to Dr. Toru Abo, an immunologist who is playing an active role worldwide.
   In his book "medical care makes illness", says about relationship between blood type and personalities (page 17-19).

   I have mentioned that a person of sympathetic nerve superiority becomes an active  "polymorph person", while parasympathetic nerve superiority becomes a generous "lymphocyte person".  However, in conjunction with this law, it was connected with blood type between human nature case.
   The connection with blood type and personalities has been pointed out for a long time, but few studies clarified the mystery scientifically till now.

   The scientific grounds are the following:

   When I summarize a level of a lymphocyte of peripheral blood of the adult whom I measured by clinical survey in every blood type.  Type O, 39%; Type B, 37%; Type A, 36%; Type AB, 34%; (object: 5,000 people).  Dr. Fukuda Minoru, my respected friend clarified this scathing observation...

Biochemical Explanation? Part 4 (March 18, 2007)

   Several experiments were televised.  For example, "Aru Aru Daijiten" on October 3, 2004...

   I was surprised by experiments of brain waves, this time, too (professor Munetaka Haida, faculty of medicine, Tokai University).  It is interesting to measure compatibility using brain waves.  On the program, he used machinery made by Hitachi Medico and measured photons which appeared from brain.  We can easily find what part of brain is activated by detecting photons.   Is it a high grade lie detector?  I have a feeling that Hitachi, Ltd. did that kind of announcement. (Mr. Haida's experiment was introduced on Korean TV -- SBS in 2006, too.)

   Another experiment by professor Noriyuki Yoshida, faculty of human and social environment, Hiroshima International University, was introduced on the same TV program.  This is also very interesting experiment to measure differences of brain waves of 40 subjects (both males and females) according to blood type.  Subjects push a button if a light is on and release it if the light is off with one's eyes closed.  Brain waves among these two states are analyzed.

     Point 1: How do brain waves react to light stimulation?
     Point 2: After light stimulation, how long does it take for brain waves to return to the original state?

   The results were fantastic!

  [Added on March 25, 2007]

   When we assume degree of brain waves excitement as [ quantity β band / (quantity of α band + quantity of β band) ], the degree was type A > type O > type AB > type B in order.  In other words, to react to stimulation of the outside world in this order.   Difference of brain wave excitement by blood type means difference of optic nerve and/or brain reaction by blood type.  Finding differences of reaction by blood type would be demonstrated at cerebrum physiology level (aside from mechanism) for the first time!  Great!!

   Type As and type Os strongly reacted to lights and remains strong reactions of brain waves, even after lights have faded.  Mr. Yoshida commented that type As and type Os are "easy to be influenced when something happens" and "worried about it".  Immediately the narrator says "always set up one's antenna to grasp the situation"; "attentive";  "considerate".

   As for type Bs, reaction is small and being restored immediately; Mr. Yoshida, says "changed one's feeling immediately"; "able go to a meal immediately even if in quarrel".  The narrator says "carry through one's pace without being controlled by surrounding situations";  "seem to be self-centric"; "keep calm".

   As for type ABs, reaction is bigger than type Bs (smaller than type As and Os) and to be restored immediately.  Mr. Yoshida says "mind and take stimulation and can do postprocessing".  "Show reaction in a mise en scene, but return to one's pace immediately"; "said to have two-facedness"; "deal with things calmly" says the narrator.

    If the result are shown properly as above, these experiments may be appreciated properly.  Then positive feedback might happen, and studies of relationship between blood type and personality may advance steadily in the near future.  I really hope so.

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Last update: March 18, 2007.

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