AR ZONE
HOW SMART IS A DOLPHIN?
These marine mammals are some of the cleverest creatures in the ocean
WORDS SCOTT DUTFIELD
Did you know?
Dolphins can recognise themselves in a mirror
Dolphins are commonly credited as being one of nature’s smartest animals, often being compared to the heightened intellect of great apes or humans. Intelligence in the animal kingdom isn’t measured solely on the size of the brain, but by how it compares to the overall mass of the animal. Neuroscientist Harry J. Jerison proposed in a 1973 paper that the ratio of body mass, actual brain size and expected brain size are related to an animal’s cognitive ability. He invented a way to accurately represent the ratio between an animal’s brain and body through a series of calculations.
These calculations are now called the encephalisation quotient (EQ), taking the volume of the brain to the volume of its expected body size into account. An EQ score compares one species’ ratio to other similarly sized animals. For example, humans have the highest EQ of any primate, scoring between 7.4 and 7.8. This means that a human brain is seven to eight times bigger than an average mammal of comparable size. The EQ score of a bottlenose dolphin is around 5.2.