It was in India in 2013, that dolphins gained the status of “non-human persons.” To most, it was entirely unprecedented to see dolphins receiving their own ‘dolphin rights’, as it were. This provoked greater research into dolphin behaviour and psychology, to determine whether dolphins do in fact share the same traits as humans, enough to render them ‘people’.
It was discovered that they did, to an alarming degree. Dolphins were found to recognise themselves in a mirror experience emotion; have individual personalities, and understand complex gestures made by humans. It was further acknowledged that Dolphins could understand sign language words, and interpret the syntax of language, a trait highly suggestive of intelligence. They could recall events and change their behaviour as a result of previous experiences, and they could use echolocation to detect objects over 70 metres away. Cognitive psychologist, Diana Reiss even suggested that dolphins could “learn to poke an underwater keyboard to request toys to play with.” She further declared that parallels could be drawn between the learning capabilities in small children and dolphins. So, if dolphins are intelligent enough to be classified as people, how do their brains differ from other animals?
To answer that, we must turn to the evolutionary paths of both dolphins and other species. The last common ancestor of humans and monkeys existed roughly six million years ago. In contrast, Cetaceans (the collective name for dolphins, whales and porpoises) diverged from the mammal lineage some 55 million years ago, and cetaceans and primates have not shared an ancestor for 95 million years. Therefore, primates and cetaceans have existed on two very different evolutionary trajectories for an extended period of time, resulting in both different bodies and different brains.
It is estimated that 34 million years ago, dolphins existed as big creatures with teeth akin to those of a wolf. Scientists suggest that around this time, the dolphin’s ancestors experienced a period of significant oceanic cooling, that altered food stores and the environment in which the creatures lived. As a result, dolphins altered their hunting customs. Their imposing teeth became smaller, the size of a dolphin’s teeth today, and their brains grew in size. Dolphins began to hunt schools of smaller fish collectively, rather than individuals hunting large fish alone. It is understood that with oceanic cooling, came the beginnings of echo location, notably in changes to the inner ear bones in dolphins at the time. As such, dolphins became more communicative and social, with the means and the need to speak with one another, and probably more intelligent as a result.
It is likely that before we overtook them, dolphins were the most intelligent creatures on the planet (more so, even, than chimpanzees), as relative to body size, a dolphin’s brain is one of the largest among the animal kingdom. Some scientists theorise that dolphins have larger brains to process the information from their echolocation system, although this cannot be proven. Nevertheless, it is still widely acknowledged that a large brain is more likely to evolve in order to support more complex cognitive abilities.
A dolphin’s extremely complicated neocortex - the segment of the brain responsible for problem solving - is accountable for a human-like intelligence. Individual whistles produced by dolphins demonstrate a self-awareness, (the knowledge that one exists as an individual being), that is present in the brain’s pre-frontal cortex. Besides dolphins, this awareness appears to only exist in humans and large brained primates. Furthermore, a dolphin’s well developed paralimbic system is essential to processing emotions, a trait that is integral in the forging of social and emotional connections between dolphins. Von Economo neurons (known as Gangly neutrons) have been discovered within dolphins’ brains; these are present in humans and apes, two of the most intelligent creatures on the planet, and have been linked to social cognition, emotional intelligence, and even theory of mind—the ability to perceive what others are thinking. To add to this, the degree to which the cerebral cortex is folded is known to be a measure of intelligence. The more folded the cortex, the more room within the brain to house additional neurons (brain cells) with which to perform processing of information. It is widely accepted that the only animal to have a more folded cortex than man is the dolphin, acting as an indication to just how smart the creatures are.
As of yet, scientists have not discovered a method through which to accurately quantify intelligence in animals. Thus, we must rely on the composition of the dolphin’s brain, and the many astounding feats dolphins continue to perform daily, as evidence of their innate intelligence. Although it is unlikely that dolphins will take over the world at any point in the near future, there is a lot to be learned from these loquacious creatures—the decoding of dolphin vocalisation, particularly, being one of the greatest enigmas of the present. However, the question persists, will our efforts be in vain if the very species we would attempt to study, is rendered extinct?
By Schuyler Daffey