2025 Volume 42 Issue 1 Pages 57-62
Mirror self-recognition (MSR) is a skill to recognize own reflection in a mirror as oneself, and is considered to be evidence that an individual animal has self-awareness. Since it was first reported in chimpanzees in 1970, MSR has been found in some species, but the level of self-awareness represented by MSR and hypotheses regarding its evolution remain unclear. The reasons for this include the fact that an animal’s failure to pass the mark test is considered the evidence of a lack of self-awareness, and the fact that self-awareness itself is confused with what can be done because of self-awareness. Particularly there are significant debates between big-bang theory and gradual theory regarding the evolution of self-awareness, and between kinesthetic visual matching hypothesis and mentalistic view hypothesis regarding the level of self-awareness. I would like to discuss how the research on MSR and photo self-recognition (PSR) in the fish cleaner wrasse, reported in 2022 and 2023, updates these hypotheses and how it will affect studies on animal behavior. I will propose a new hypothesis regarding the evolution of self-awareness by reinterpreting reported animal behaviors and their experimental results.
