I can’t tell you how many times I have been asked my blood type in Japan. I’m still too lazy, though, to find out. I’m sure my mom knows, and I always forget to ask when I get blood drawn.

In Japan, people think that blood type determines personality. They have books and games on the subject, and people here are almost religious in their conviction that the blood type-based predictions are accurate. I’ve seen television shows that only give one side of the debate. They’ll show an experiment that divides children up by blood type and accurately predicts their actions and then fail to show the countless experiments that produce less than favorable results for the hypothesis. Satoru Kikuchi, associate professor of psychology at Shinshu University, says, “Blood types, determined by the proteins in the blood, have nothing to do with personality. It’s simply sham science. The idea encourages people to judge others by the blood types, without trying to understand them as human beings. It’s like racism.”

For the most part, it’s just funny to see them making such a big deal of it. In fact, I guess one of the reasons I always “forget” to ask the doctor my blood type is that I love seeing the expression on people’s faces when I tell them that I don’t know my blood type.

It can get serious, though, as this article describes, with sports positions and even jobs being determined by blood type.