Contributed by Marielle Grenade-Willis
Cetaceans have been known to showcase an array of intricate social, emotional, and physical capabilities. Most recently, a new study on two captive dolphins housed at the National Aquarium in Baltimore, Maryland found that these clever cetaceans can in fact recognize themselves and at a much earlier age than what has been observed in both humans and chimpanzees. Using an underwater mirror and viewing the dolphins’ behavior over a three year period, the scientists found that: “[…] self-directed behavior emerged in a dolphin at 7 months of age […] Both dolphins exhibited predominantly self-directed behavior at the mirror after minimal mirror exposure and both passed subsequent mark tests. […] In this study we considered the dolphins’ performance of self-directed behavior at the mirror the primary evidence for MSR and their subsequent passing of mark tests, when we were able to conduct them, as further confirmation of this ability.” Interestingly, the dolphins expressed a suite of “solitary play” behaviors while interacting with the mirror suggesting that the dolphins may know how to use it as a tool for their own entertainment. Play is one of Martha Nussbaum’s Central Capabilities and perhaps more studies on the self-recognition of marine mammals will unearth more about how these creatures express this capability by themselves and with their cohorts.