In Japan, Korea, and to a less extent in a few other countries some people believe in a connection between a person’s blood type and their personality. There is no scientific basis for this belief but it still persists.

This RLE can be used to demonstrates how ideas are influenced by existing beliefs. Consider someone who believes in the blood type / personality theory. If they find out a friend is blood type A, they will try to make connections between their friend and the personality characteristics in the chart above for type A. They will likely ignore (consciously or unconsciously) the ways their friend matches the personality characteristics of the other blood types.