In researching a connection between the two markers, one study found that the platelet MAO activity of subjects with blood type O was significantly lower than that of subjects with other blood types, Īlcoholism, antisocial personality and impulsivity. The ABO blood group system and platelet monoamine oxidase (MAO) activity are known to be two genetic markers for affective disorder. Ĭongenital dopamine beta-hydroxylase deficiency is caused by mutation in the gene encoding dopamine beta-hydroxylase on chromosome 9q34, also the ABO locus. Some medical studies show variation of hormones and enzymes which other studies have associated with personality changes: Individuals have varying levels of the enzyme dopamine beta hydroxylase and catecholamine hormones according to their blood type as a result of genetic linkage of nearby genes on chromosome 9 (the locus for ABO blood group in humans). The results produced 13 significant differences at a confidence interval of p<0.05 and 11 at p<0.01, the most conclusive finding occurring in the association between the P blood group system and anxiety. One such study, by the psychologist Raymond Cattell, examined blood samples of 323 Caucasian Australians for 17 genetic systems including 7 blood groups and 21 psychological variables. While scientific study has shown that people of specific blood types may be more prone to certain illnesses, little research has been carried out on the correlation between blood type and personality traits. Because of this he has been heavily assailed by the Japanese psychological community, although his books are phenomenally popular. Nomi's work was largely uncontrolled and anecdotal, and the methodology of his conclusions is unclear. It was revived in the 1970s with a book by Masahiko Nomi, a lawyer and broadcaster with no medical background. The craze faded in the 1930s as its unscientific basis became evident. In conclusion, Furukawa suggested that the Taiwanese should intermarry more with the Japanese in order to reduce the number of individuals with type O blood. The reasoning was supported by the fact that among the Ainu, whose temperament was characterized as submissive, only 23.8% had type O. Based on the finding that 41.2% of a Taiwanese sample had type O blood, he assumed that their rebelliousness was genetically determined. 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'. Insurgencies in 1930 and in 1931 killed hundreds of Japanese settlers. After the Japanese occupation of Taiwan following Japan's victory over China in 1895, the inhabitants tenaciously resisted their occupiers. His motivation for the study appears to have derived from a political incident. In another study, Furukawa compared the distribution of blood types among two different ethnic groups, the Formosans in Taiwan and the Ainu who live in Northeast Asia, especially Hokkaidō. The breeding program therefore ended up with miserable results - most of the army selected by the project lost their lives.

The study used no more than ten to twenty people for the investigation. The idea quickly took off with the Japanese public despite his lack of credentials, and the militarist government of the time commissioned a study aimed at breeding the soldiers. He was a professor at Tokyo Women's Teacher's School.

The theory first reached Japan in 1927 in Takeji Furukawa's paper 'The Study of Temperament Through Blood Type' in the scholarly journal Psychological Research. Those distortions were debunked before Nazi Germany invoked race laws like the Nuremberg Laws, where the wording 'German blood' is figurative for Aryan lineage. This fact was used by early Nazis to further ideas of supremacy over different races. Asian people having a higher percentage of Type B). Ethnic studies did show different blood group distributions across the world (e.g.

The ABO blood group system is widely credited to have been discovered by the Austrian scientist Karl Landsteiner, who found three different blood types in 1900.

B negative blood type personality