The mirror test is an experiment developed in 1970 by psychologist Gordon Gallup Jr. to determine whether an animal possesses the ability to recognize itself in a mirror. It is the primary indicator of self-awareness in non-human animals and marks entrance to the mirror stage by human children in developmental psychology. Animals that pass mirror test are: Humans older than 18 mo, Chimpanzees, Bonobos, Orangutans, Gorillas, Bottlenose Dolphins, Orcas (Killer Whales), Elephants, and European Magpies. Others showing signs of self-awareness are Pigs, some Gibbons, Rhesus Macaques, Capuchin Monkeys, some Corvids (Crows & Ravens) and Pigeons w/training. (Sorry Kitty!)