Supplement 1

Personality tests cannot detect blood-type differences properly

Psychological personality tests cannot detect correct differences of personality based on blood types.

Researchers often use a famous personality test called the "Big Five". This test cannot detect correct differences, though used globally. After all, to analyze relationship of blood types and personality, current personality tests might be powerless.
Papers that used the Big-Five test are as follows. No or little difference found (*1) or inconsistent results (*2).

No.	Researcher(s)	No. of Subjects	Country
1	Kenneth M. Cramer, Eiko Imaike (2002) *1	419	Canada
2	Mary Rogers, A. Ian Glendon (2003) *1	360	Australia
3	Kunher Wu, Kristian D. Lindsted et al. (2005) *2	2681	Taiwan
4	Sohyun Cho, Eunkook M. Shu et al. (2005) *1	204	Korea
5	Zirak Morandlou Hossein (2012) *1	160	Iran
6	Jaroslav Flegr, Marek Preiss et al. (2013) *1	502	Czech
7	Rebecca Anders Buckner, John E. Buckner (2014) *1	182	U.S.A.
8	Fatemeh Beheshtian, Roghayeh Hashemi et al. (2015) *2	160	Iran
9	Mohammad Sharifi, Hamza Ahmadian et al. (2015) *2	400	Iran
10	Amreen Nahida, Nandini Chatterjee (2016) *2	100	India
11	Yoshihiro Kawana (2003) *1	33	Japan
12	Keiichiro Mori, Mutsuo Harano et al. (2005) *1	172	Japan
13	Yoshoo Kubo, Yukiko Miyake (2011) *1	273	Japan
14	Takeshi Shimizu, Masato Ishikawa (2011) *2	866 1503	Japan

References:

Kenneth M. Cramer, Eiko Imaike (2002) Personality, blood type, and the five-factor model. Personality and individual Differences, 32, 621-626.
Mary Rogers, A. Ian Glendon (2003) Blood type and personality. Personality and Individual differences, 34(7), 1099-1112.
Kunher Wu, Kristian, D. Lindsted, Jerry W. Lee (2005) Blood type and the five factors of personality in Asia, Personality and Individual Differences, 38, 797-808.
Sohyun Cho, Eunkook M. Shu, Yoenjung Ro (2005) Beliefs about Blood Types and Traits and their Reflections in Self-reported Personality. Korean Journal of Social and Personality Psychology, 19(4), 33-47.
Zirak Morandlou Hossein (2012) The Relationship between Students’ Personality Traits and Their Blood Types, Journal of Health and Devalopment, 1(3):221-226.
Jaroslav Flegr, Marek Preiss et al (2013) Toxoplasmo-sis-Associated Difference in Intelligence and Personality in Men Depends on Their Rhesus Blood Group but Not ABO Blood Group, PLoS One.
Rebecca Anders Buckner, John E. Buckner (2014) It is not in your blood: exploring claims that blood type and personality are linked, Skeptic [Altadena, CA], 19(3):24-27.
Fatemeh Beheshtian, Roghayeh Hashemi and Zolfaghar Rashidi (2015) The Five Personality Factors over the Students with Four Blood Types, Journal of Applied Environmental and Biological Sciences, 5(8):45-49.
Mohammad Sharifi, Hamza Ahmadian and Ali Jalali (2015) The relationship between the big five personality factors with blood types in Iranian university students, Journal of Chemical and Pharmaceutical Research, 7(5):233-240.
Amreen Nahida, Nandini Chatterjee (2016) A study on relationship between blood group and personality, International Journal of Home Science.
川名好浩（川村学園女子大学）血液型性格判断－Big Five でのプロフィール－日本心理学会第67回大会論文集 p156 (2003)
森圭一郎・原野睦生・江藤義典・津田彰・内村直尚（久留米大）・中川康司（奈良県医大）TCIとBig5による性格とABO式血液型の関連解析日本生物学的精神医学会プログラム・講演抄録第27巻 p306 (2005)
久保義郎・三宅由起子血液型と性格の関連についての調査的研究吉備国際大学研究紀要（社会福祉学部）第21号 p93-100 (2011)
清水武・石川幹人ＡＢＯ式血液型と性格との関連性―主要５因子性格検査による測定 (2011)

Reanalysis of global Big-Five surveys is discussed in the following Korean paper.

Sung Il Ryu, Young Woo Sohn (2007) A Review of Sociocultural, Behavioral, Biochemical Analyzes on ABO Blood-Groups Typology. Korean Journal of Social and Personality Psychology, 21 (3), 27-55.

In this paper, Dr. Sohn said,

We concluded that blood types and personality are not related in all studies that used the Big-Five Factor model (So Hyun Cho, 2005; Cramer, 2002; Rogers, 2003; Kunher, 2005).

Then we get the survey data from So Hyun Cho (2005) and reanalyzed individual question items in detail. Significant relations with blood types were found in 10 items. [See the table below]

Type	Characteristics	Question Item	Difference
A	[Consideration]	Cooperative Warm Kind Admirable	B (p = .001) AB (p = .026) B (p = .046) AB (p = .028)
B	* Non-creative	Non-original	A (p = .040), O (p = .034)
O	[Introversion] [Extraterrestrial] [Instability] [Thinking]	Shy Shy Energy-rich Disordered Cooperative	A (p = .009) A (p = .010), B (p = .013) B (p = .034) B (p = .040) B (p = .047)
AB	[Logicality] [Consideration]	Rational Cooperative	B (p = .018) B (p = .023)

(*) Indication: an item that is not organized into separate categories

Obviously, the Big-Five model cannot detect actual blood-type differences. In other words, differences in individual "blood-type-characteristic" questions must have appeared, but they had been canceled out in the process of consolidating the results into the five factors. Some differences might have decreased and the others might have disappeared ...

Dr. So Hyun Cho also said in his paper (2005),

Participants also rated their own personality on two different measures - the Big 5 inventory and a set of personality traits most frequently associated with each of the 4 blood types (stereotypic traits). Consistent with past research, no meaningful relationship emerged between the Big 5 traits and blood type. Interestingly, however, self-ratings on the stereotypic traits revealed a self-fulfilling pattern. Those who firmly believed in the validity of the blood type stereotypes were more likely to report his/her trait in a stereotype-consistent direction (e.g., a blood type A person reports that she indeed is very "timid").

As mentioned before,

Results of self-report-type questionnaires are usually considered as "personality itself" (not only "recognition of self's personality").

Source: Toshinori Shirasa & Takuji Iguchi, An Introduction to blood-type personality research (1993) 白佐俊憲・井口拓自血液型性格研究入門―血液型と性格は関係ないと言えるか

A deep sigh ...

For further information, visit my website.