Recently, an article of Human Science ABO Center's blog

Relationship between brain activities and blood types -- What I learned from the experiment (in Japanese)

https://human-abo.blogspot.jp/2017/05/blog-post_24.html

was post.

Source: Blog of ABO Center

The Human Science ABO Center and Dr. Munetaka Haida (Tokai University) have been conducting a joint research on relationship between brain function and blood types for over 10 years.

According to this article, a "photo topography" experiment to measure activities of the human brain showed a spectacular contrast.

Type A = activity of the left brain is high (logical activity)

Type B = activity of the right brain is high  (sensory activity)

Although, there were relatively less differences between Type O and Type AB:

Type AB = using both the left and the right brain simultaneously 

Type O =  using both the left and the right brain alternatively

From these results, it can be said that blood types, the left and the right brain are related to each other.  We might be one step closer to the truth!