“Humans are the only animals that can recognize themselves in a mirror.”

For a long time, it was widely believed that the ability to recognize oneself in a mirror was a unique trait, primarily associated with humans and our closest primate relatives, the great (Review) apes. This perception often stemmed from early psychological studies, particularly the development of the mirror self-recognition (MSR) test in 1970, which initially reinforced the idea that such a sophisticated form of self-awareness was rare in the animal kingdom. The test involves placing a mark on an animal's body that can only be seen via a mirror; if the animal then touches or examines the mark on its own body, it suggests self-recognition.

However, scientific understanding has significantly broadened, revealing that self-awareness is not exclusive to humans or great apes. Over the decades, a growing body of evidence from various studies has shown that numerous other species also demonstrate this remarkable cognitive ability. Bottlenose dolphins, for instance, have passed the mirror test, exhibiting self-directed behaviors when presented with their reflections. Asian elephants have also shown self-recognition, inspecting marks on their bodies using a mirror. Even more surprisingly, species from vastly different evolutionary branches, such as Eurasian magpies and cleaner wrasse fish, have successfully navigated the mirror test, challenging previous assumptions about animal intelligence and perception.

This misconception likely persisted due to a combination of factors, including an anthropocentric bias that often places human cognitive abilities at the pinnacle of intelligence. The initial focus of the mirror test on visually oriented, social species like primates may have also contributed to the narrow view of self-awareness. Furthermore, the complexities of studying animal cognition mean that research into diverse species is ongoing, and findings that challenge long-held beliefs take time to become widely known and accepted.