Consciousness and the Mirror Test

"The Mirror test is a measure of self awareness developed by Gordon G. Gallup. Animals which have passed the mirror test are chimpanzees, orangutans, dolphins and humans. Surprisingly, gorillas have not passed the test. Human children tend to fail this test until they are at least 3-4 years old."
-- http://en.wikipedia.org/wiki/Mirror_test

I don't find it very scientific, but it's interesting.