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).