Blog Post

Does Blood Type Determine Personality?

26341666_sMV writes: “I laughed out loud when I read the title of an article that blood type determines personality. I did not read the article because it sounded absolutely ridiculous. Have you heard of this nonsense? Could you please discuss it and warn others?”

The belief that a person’s blood type determines certain personality traits is widely accepted in Japan and Asia in spite of the fact that there’s very little science behind the notion.

According to, the idea began in Japan in the 1920’s when an academic named Takeji Furukawa published “The Study of Temperament Through Blood Type.” The research paper discussed how blood type determines certain personality traits. Even though the research was later found to be lacking, the idea captivated the imagination of the Japanese public.

It wasn’t until the 1970’s when a journalist named Masahiko Nomi – who has no medical background - published a series of books on the subject that became instant bestsellers and the idea once again became a sensation in Japan. Nomi’s son, Tashitaka followed in his father’s footsteps and continued to promote the theory.

“Now blood typing can be found all over East Asia, with many in Japan, South Korea and Taiwan using the theory in their everyday life,” reports. “Just like the western phenomena of horoscopes, blood typing can be found in many newspapers and magazines. They even have online dating websites that match you by your blood type. You can even find certain drinks marketed towards different blood types.”

According to the theory, people with blood type A tend to be conservative and introverted and very loyal to those they love. Blood type B is more creative, independent, self-centered, and passionate but shallow. Blood type O – which is one of the most common types – is friendly, optimistic, energetic and outspoken. Blood type AB – which is the least common blood type – is more intelligent than the rest of us, focused, critical, indecisive and likes to hide their feelings.

So is any of this true?

According to this article appearing in The Japan Times, “There is . . . no scientific basis for believing that blood type plays any role in determining personality. This has been demonstrated again and again, and most recently in a large-scale study of more than 10,000 people in Japan and the United States that was recently reported in the Japanese Journal of Psychology.”

Instead, personality is believed to be the result of a combination of four factors - physical environment, heredity, culture and particular experiences.

However,  just like horoscopes, a lack of scientific evidence doesn't stop people from believing in it.

For example, when Japan’s Minister for Reconstruction, Ryu Matsumoto, resigned in 2011 for making offensive remarks about the people in areas hit by the earthquake/tsunami disaster, he blamed his blood type.

"My blood's type B, which means I can be irritable and impetuous, and my intentions don't always come across,” he said, according to the BBC. "My wife called me earlier to point that out. I think I need to reflect about that."

The bottom line is that there's no more proof that our blood type determines our personality than the position of the stars.