It shows racial bias. You have pre-set ways of thinking and associating words or feelings with people. Most people begin to cross these at some point, and we get specific people associated with specific meanings or feelings. And if you dont believe me, look at some of the crazy figures about how much time an average black dude will serve for a given offense versus the time a white dude will. It plays into our everyday lives and we dont notice it.
Its a cool test. Definitely eye-opening.
Oh yes, and if this psych stuff is cool to any of you, read "Blink" by Malcolm Cladwell.