Blood type personality theory

Blood type personality theory is a way of looking at people's personalities based on their blood type. It is based on a belief in Japan that people's personalities are linked to their blood type. People's blood type is determined by looking at the different kinds of molecules that are on the surface of their red blood cells. In Japan, people with the blood type O are thought to be outgoing and energetic, type A people are seen as more sensitive and reliable, type B people are often creative thinkers, and type AB are seen as flexible and in between types A and B.