In class we recently discussed the harmful effects of orca captivity on these animals’ psychological states. This led me to wonder how captivity may affect dolphins; another popular cetacean in captive settings. It is no secret that dolphins are highly intelligent animals, but what skills do they possess that suggest this intelligence and how might this intelligence indicate they may be emotionally or psychologically suffering in captivity? Lori Marino, a senior lecturer at Emory University, studies these exact issues in dolphins.
Marino conducted a study in 2000, which tested dolphins’ ability to recognize their selves in a mirror. Although this may seem like a simple task, prior to this study only humans and great apes had displayed this behavior. Humans don’t preform this behavior until 18-24 months of age, when other abstract concepts of the self start developing. The study included two captive-born dolphins. Their bodies were marked and then they were given the opportunity to observe themselves in a reflective surface. The dolphins indicated they were aware the mirror was a reflection of themselves by exploring the marked areas of their bodies in the reflections. If the dolphins were left unmarked, they did not show the same immediate interest in looking at themselves as when they had been marked. Although this behavior cannot conclusively determine if dolphins preform other self-awareness processes, such as introspection (analyzing their own thoughts and feelings) or awareness that other dolphins have their own thoughts and feelings, it is a good start. Marino has stated that the more self-aware dolphins are the more vulnerable they may be to captive life. She believes the more aware a dolphin is of his/her present and past circumstances, the more the dolphin can feel the difference between pleasant and unpleasant situations, thus leading to rumination about the negative consequences of the current situation.
Further evidence of dolphins’ capacities for emotion and complex mental processes comes from neurological research. MRI scans reveal that features of the dolphin neocortex are expanded. The neocortex is responsible for higher-level thinking and emotional processing. The dolphin brain is also four to five times larger for their body size compared to another animal of similar size. Taken together, this behavioral and neurological research suggests that dolphins may not be happy as captive animals. Their emotional and mental abilities may enable them to perceive living in such a small, enclosed, and empty area as negatively as you or I would. Efforts to ensure the welfare of dolphins in captive settings are imperative to make these settings enjoyable for them.
“Dolphins: Second-Smartest Animals?” Discovery News. Web. 24 Feb 2015. http://news.discovery.com/animals/whales-dolphins/dolphins-smarter-brain-function.htm
Reiss, D., & Marino. (2000). Mirror self-recognition in the bottlenose dolphin: A case of cognitive convergence. Proceedings of the National Academy of Sciences of the United States of America, 98, 5937-5942.