The dolphin passes the "Miller test" which recognizes himself in the mirror earlier than a human baby

The ability to recognize yourself in the mirror by looking at yourself is called "Mirror test" and it is used as one of the measures to measure the height of animal's intelligence. Dolphin is one of the animals who pass the mirror test, but research has made it clear that you can understand yourself in the mirror from an earlier time than a human baby.

Mirror self-recognition in the bottlenose dolphin: A case of cognitive convergence
http://www.pnas.org/content/98/10/5937.full

Dolphins Show Self-Recognition Earlier Than Children - The New York Times
https://www.nytimes.com/2018/01/10/science/dolphins-self-recognition.html

In addition to humans, chimpanzees, elephants, magpies, etc. are known as animals to clear to the mirror test. Although clearing the mirror test does not necessarily mean intelligence, there are many scientists to use as an indication of intelligence, and dolphins which are thought to have high intelligence also clear the mirror test.


Dr. Dinna Les, a psychologist at Hunter College, looked at the time when dolphins pass the Miller Test by observing the two dolphins at the Baltimore National Aquarium for three years. In addition, it is known that human beings are about one year after birth, and chimpanzees begin to recognize their appearance in the mirror in about two years after birth.


Female Bailey and male Foster tested


When the experiment was carried out using a large mirror placed in the aquarium, the male's bailey, which had already been 14 months old, should be turned upside down in front of the mirror, playing with bubbles It was confirmed that I recognized myself in the mirror. Another baby bailey was confirmed to be able to recognize himself, for example, turning in front of a mirror or showing a gesture that he normally can not show, when he was seven months old.


In addition, an experiment was conducted to put "mark" on Foster's body and pay attention to the mark. When Foster was 24 months old, she also cleared the mark test. In addition, it is around 18 months to 24 months for a human baby to clear the mark test, so it is likely that dolphins are beginning to show self-recognition ability early on human beings.


Dr. Fran-de-Waal of Emory University, who carried out the elephant's mirror test together with Dr. Les who conducted the experiment, said, "It is known that humans change the timing of passing the mirror test by environmental factors This dolphin's mirror test is an extremely valuable experiment to ascertain the influence of the environment on self-perception. "


You can see how Bailey and Foster recognize yourself in front of the mirror, dance, play a bubble game, dance, in the following movie.

Dolphins Show Self-Recognition Earlier Than Children - The New York Times -