"The stereotypes must have arisen strictly from the mere existence of the labels."
Actually, there is an interesting history to where these (completely bogus) stereotypes came about. Wikipedia has an article on this that explains the historic roots of this fad in racism and politics. For example, Japan had a political conflict with Taiwan, and someone noticed that Taiwanese people are predominantly type O. He therefore argued that "Taiwanese rebelliousness" was genetically determined and that blood type was a marker of this. Clearly thi... (read more)
"The stereotypes must have arisen strictly from the mere existence of the labels." Actually, there is an interesting history to where these (completely bogus) stereotypes came about. Wikipedia has an article on this that explains the historic roots of this fad in racism and politics. For example, Japan had a political conflict with Taiwan, and someone noticed that Taiwanese people are predominantly type O. He therefore argued that "Taiwanese rebelliousness" was genetically determined and that blood type was a marker of this. Clearly thi... (read more)