New research suggests that dolphins are more intelligent than previously believed and should be regarded as “non-human persons”.

The relative high intelligence of dolphins compared to other animals has always been evident. Dolphins display both culture and language, and have been seen to demonstrate altruism not only for each other but for whales and humans. New research indicates that they may be even more intelligent than previously believed, and that humanity should reappraise how it classifies and treats them.

Behavioural studies have shown that dolphins can possess distinct personalities and self-awareness, and they can think about the future.

“In one case a rescued dolphin in South Australia, taught to tail-walk during recuperation, in turn taught the trick to other wild dolphins in the Port Adelaide river estuary when she was released. According to marine biologist Mike Bossley it was "like watching a dance craze take off", with the dolphins apparently learning the trick just for fun, since tail-walking has no natural function.”

Psychology professor Diana Reiss of the City University of New York was able to teach dolphins a rudimentary language based on symbols. This capacity for intelligence is believed to derive from dolphin’s large brains: the ratio of brain mass to body size is second only to the human brain, larger even than that of the chimpanzee.

Several leading academics believe that this evidence of intelligence indicate that it may not be ethical to keep dolphins for amusement, or kill them for food. Thomas White, professor of ethics at Loyola Marymount University, says the new research supports his idea that dolphins should be regarded as ‘non-human persons’, with extra protection and the right to be treated as individuals.

Should our knowledge of dolphin intelligence change the way we see them? Should especially intelligent animals be classified and treated differently?