Ever since Ancient Greece, the dolphins have been held in high esteem for their friendliness and intelligence. But are they clever as we think?
Moments after John Lilly cracked open the dolphin’s skull, a bulging pink mass emerged. Instantly he knew he’d made an important discovery. This animal was huge: even bigger than a human brain.
This year was 1995, and after examining the freshly harvested brains of half a dozen bottle-nose dolphins, Lilly, a neuroanatomist, concluded that these fish-shaped aquatic mammals must possess the intelligence to rival our own.
When Lilly made his discovery the link between intelligence and brain size seemed simple: the bigger the brain, the smarter the animal. Humans, without enormous brains stuffed into our swollen craniums, were obviously the smartest species, so it followed but dolphins must also be pretty darned clever.
But research has since shown that the dolphin’s claim to fame as the smartest non-human isn’t that clear-cut. Crows, octopuses, even insects have all demonstrated feats of brainpower to rival the dolphin, and they don’t possess nearly as much grey matter. So are dolphins really as smart as we think?
The EQ test- The Encephalization Quotient(EQ) is a measure of how an animal’s brain is compared to what we’d expect to see for its body size. According to some calculations, human has the largest EQ(7), with the brains seven times larger than you’d expect for our bodies. Dolphins are the in the number two spot, with species like the rough-toothed dolphin having an EQ of about 5.
But when attempting to match EQ ratings to intelligent behaviour in animals, results are mixed. Large EQs correlate with the ability to cope with novel environments or the productions of diverse behaviours, but not with tool us or imitative ability. To further muddy the picture, the calculations of EQ itself has come under criticism in recent years.
Depending on the data that’s fed into the model, humans have normal-sized brains for our bodies, whereas gorillas and orangutans have abnormally large bodies for their standard-sized brains.
Simple having a big brain- or a large EQ is by no means a guarantee that an animal will display intelligence. But it wasn’t just brain size that intrigued Lilly. Inside the dolphin skull, he found an outer layer of brain tissues that, much like the human brain, was folded in on itself, like crumpled paper stuffed into a thimble.
The outer layer of the mammalian brain, called the cortex, is involved in complex cognition in humans, including our language skills and self-awareness. As it turns out, the dolphin cortex is larger than the human cortex. So what might this mean?
Many species that pass the test for self-awareness(like the mirror self-recognition test) have a relatively large cortical structure in the front of their heads. it’s this ‘frontal cortex’ that is likely responsible for the mirror self-recognition skills of chimpanzees, gorillas and elephants. Dolphins passed this test too.
But therein lies the rub: dolphins don’t have a frontal cortex. Their oversize cortex is squished into areas around the sides of their skull, leaving the front of their brain oddly concave. And since magpies which can also themselves in mirrors, don’t have a cortex at all, we’re still left scratching our heads as to which parts of dolphins’and magpies brain are involved in self-recognition. Maybe, like magpies, dolphin rely on or non-cortical structures to recognize themselves in mirrors. What exactly the dolphin cortex is doing and why it’s so large is an unsolved mystery.
Name that smart whistle!
This isn’t only the only enigma surrounding dolphin intelligence. Over the years the debate about how dolphins’ brains relate to their behaviour has been so exasperating that marine mammal expert Lance Barrett-Lennard was forced to conclude that “a dolphin could have a brain the size of a walnut and it wouldn’t affect the observation and they live very complex and social lives”.
Although Lilly might have objected to the walnut comment, the idea of dolphins as socially complex beings is a sentiment with which he would have agreed. While performing rather unpleasant invasive experiments on the brains of living dolphins, he noted that the dolphins would often call out to each other, and would seek comfort from one another.
He would seek comfort from one another. He believed that this was evidence that dolphins were both socially complex might be as a complex as human language. Fifty years later, there is evidence to suggest that Lilly was not too far off the mark.
Information Collected – https://www.wikipedia.org/ and other verified sources
Also, check this out!