ABO blood group system A and B antigens, but contains anti-A and anti-B. The following year, his students Adriano Sturli and Alfred von Decastello discovered the fourth type (but not naming it, and simply referred to it as "no particular type”). In 1910, Ludwik Hirszfeld and Emil Freiherr von Dungern introduced the term 0 (null) for the group Landsteiner designated as C, and AB for the type discovered by Sturli and von Decastello. They were also the first to explain the genetic inheritance of the blood groups.) Czech serologist Jan Janský independently introduced blood type classification in 1907 in a local journal. He used
Blood type personality theory methodology of his conclusions was unclear. Because of this, he was heavily criticized by the Japanese psychological community, although his books remain popular. His son, Toshitaka Nomi, continued to promote the theory with a series of books and by running the Institute of Blood Type Humanics. He later established the Human Science ABO Center for further research and publication in 2004. Some researchers believe blood types are associated with personality traits. Many medical surveys have been conducted, such as those for hormone secretion traits (DBH, COMT, MAO etc.), or the blood-type antigens in neurons, or the antigens expressed on surfaces