Note. Some characteristics seemingly contradict others. Unlike personality psychology, Nomi assumed that responses to stimuli were nonlinear.
His questionnaire results showed that the effect size was small to medium, with differences by blood type ranging from 10-20% in absolute response rates. In studies of blood type distributions, Nomi found that Japanese prime ministers were more likely to be O, foreign ministers O or AB, education ministers more likely A or AB; professional baseball hitters O or B, high-ranking sumo wrestlers A, and so forth; all of which were supported by statistically significant differences. P-values varied widely from below 0.001 to 0.05, dependent upon sample size and other conditions (Nomi, 1978; Kanazawa 2019).
Presently, many Japanese people believe in the relationship between blood type and personality. For example, in a 2015 online questionnaire conducted by Fuji Television Networks, one of the major television networks in Japan, found that 68.7% of a 201,119-person audience believed in the relationship between blood type and personality (Fuji Television Networks, 2015). These results are in accordance with past observations: a 1986 survey conducted by NHK, the Japanese public broadcaster, found that 75% of 1,102 respondents believe in the relationship (NHK Broadcasting Culture Research Institute, 1986).

Results of Academic Studies

Questionnaires by psychologists created the following images of each blood type. Yamazaki and Sakamoto conducted a survey of 177 female undergraduate students on the 24 personality traits in the annual opinion poll data by JNN Data Bank, a department of Tokyo Broadcasting Corporation, which is one of the major television networks in Japan. The results of the top three (yes-no scales, multiple answers) are displayed in Table 2 (Yamazaki & Sakamoto, 1991 & 1992).