> What I've Learned. Why Does Japan Care so Much about Blood Types? YouTube, <https://www.youtube.com/watch?v=GPhEgtChaag>. Accessed 16 Aug. 2021. # Why does Japan care so much about Blood Types? - Around 40% of Japanese people believe blood type contributes to personality, and 38% of doctors - In 1910, Ludwig Hirszfeld and Emil von Dungern proved that blood type was an inherited trait - Around this time, it was found that Japanese had 20% of blood type B people compared to 10% of Europeans - Von Dungern used this to say that Asians were inferior, prompting Furukawa Takeji to investigate the relationship between blood type and personality - He analysed relatives: blood type A people were inactive, and B and O were assertive - He went on and investigated 319 more people, publishing a 1926 paper detailing blood type personality traits: "Research and Temperament Due to Blood Type" - In 1931, he published a sensational article in a famous economics magazine advertising his findings, but was dismissed by the Japanese Society of Legal Medicine in 1933 - 40 years later, in 1973, public interest in blood type boomed again thanks to journalist Nomi Masahiko's book _Blood Type Anthropology_ - He pointed out that many successful Japanese people had blood type O or B. - In his 1978 book _New Blood Type Anthropology_, he showed that blood type O people were more likely to be involved in car accidents, and type A people were less likely to be - But in 1995, the story was flipped - In 2018, Takeda Tomohiro published _It's Really Amazing! Blood Types_, where he shows that the top Japanese batters are blood type O or B. - But if you look at the distribution of blood types across the 786 players of the Japanese pro baseball league, it is hardly different from the national distribution - Blood type O people are less likely to get pancreatic cancer, Malaria, diabetes and to develop cardiovascular disease and cognitive decline, thanks to lower levels of von Willebrand factor, a blood clotting agent - They are therefore more likely to die from severe trauma - Peter J. D'Adamo, _Eat Right For Your Type_ - A 2014 study found that the recommended diets were beneficial to everyone no matter what their blood type was - D'Adamo claims that type O people have a stress response centered on fight-or-flight - He explains that dopamine is converted into norepinephrine by an enzyme called dopamine beta-hydroxylase (DBH) and that type O people have higher levels of DBH which causes higher levels of anxiety - A study by Donna Hobgood explains that the gene for DBH is on chromosome 9q34 and is tightly linked with the ABO gene - Hobgood says that low activity DBH would relate to impulsive behaviours, and high DBH to persistent behaviours - In 2015, Japanese researchers investigated further, showing that type A people were more persistent, but also said that those were preliminary results and that this data was inconsistent with other previous studies - A 2014 study looking at 10,000 people from Japan and the US found that blood type accounted for less than 0.3% of the total variance in personality