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by Leanne Louie
Babel fish and Vogons may be the stuff of fiction, but The Hitchhikers Guide To The Galaxy was right about the intelligence of one marine species: dolphins.
Emerging science suggests that dolphins, alongside their toothed whale cousins (orcas and porpoises), may be the world’s ‘second-smartest animal,’ rising even above the great apes.
The larger an animal’s brain relative to its body, the more brain matter is available for complex cognition. The human encephalization quotient (EQ) is around 7.5— meaning our brains are 7.5 times as massive as expected of an animal our size. Toothed whales have EQ second in size to humans, ranging from 2 to 5.
Why Bigger Brains?
Why did such different species both evolve highly developed brains? Although we differ in many regards, whales and humans also share quite a few characteristics—we both evolved as hunters, live in social communities and lack penile bones. (Okay, only two of those are relevant.)
Social, community-living organisms tend to have higher EQs than similar but solitary animals. Living in complex, interactive societies, humans have the most highly developed brains in the animal kingdom. Among the cetaceans, it’s the toothed whales, who live in groups, rather than the more solitary baleen whales that have the highest EQs.
Research indicates that diet also seems to significantly influence brain size. Given the forethought and planning required of hunters, carnivores tend to have high EQs. The high-energy carnivorous diet also allows for more neural development than a diet of plants or insects.
As both highly social animals and adept hunters, it’s clear why toothed whales have such high EQs. In some respects, their brains actually rise above ours. Some of their neural transmission speeds are faster, and their brains have a higher ratio of surface area to volume. Caused by increased convolutions (the folds, or ridges found on the surface of the brain), a large brain surface area is known to be a strong sign of complex intelligence.
Toothed whales’ intellectual capacity is also evident in their everyday behavioural patterns. Dolphins and orcas can interpret and respond to complex directions from trainers, indicating an understanding of symbolic representations. Dolphins also use tools efficiently, with some species using sponges, shells, and self-blown bubble nets to streamline hunting techniques. They’re even able to recognize themselves in mirrors, a rare ability that indicates a sense of self-knowledge and awareness.
The ability that truly sets toothed whales apart from other animals is their capacity for learning. In captivity, they’re able to master complex routines set out by trainers, showing a particular aptitude for mimicry. Dolphins and orcas alike are expert imitators, often mimicking each other’s actions and even human postures. Imitation is one of the greatest indicators of social learning abilities.
In the wild, toothed whales display an even wider array of learned abilities. Orca mothers instruct their young in hunting techniques and dolphins employ learned tool-use. In the northern Pacific, different orca families are known to communicate using unique dialects learned from their peers. These behaviours are considered to be indications of culture— the transmission of learned behaviour.
Cognition and Identity
The advanced learning abilities of toothed whales imply a great depth of social cognition— awareness of and attention to the actions of others. Indeed, scientists have discovered a special type of cell in the brains of some cetaceans, one previously found only in humans and great apes. Called spindle cells, they’re involved in emotions and social bonding, and early research suggests some whales (including orcas) could have even more spindle cells than humans.
Furthermore, the paralimbic brain region, an area involved in the processing of emotion, is larger and more elaborate in orcas than humans. This leads to researchers like Lori Marino (the neuroscientist featured in the documentary Blackfish) to speculate orcas might lead highly emotional lives, perhaps even more so than our own.
In an interview with The Raptor Lab, Marino presented some other interesting possibilities. She proposed that toothed whales could have a distributed sense of self, almost an inability to separate their own identities from the collective. This theory would certainly explain a few of their more interesting behavioural patterns, like their synchronized movements and mass stranding events— where entire groups of whales beach themselves for no apparent reason.
Whether there is any truth to this theory of collective identity or not, it’s unquestionable that toothed whales are capable of emotional bonding and long-term social relationships. Instead of fleeing, whales released after being netted have been observed to remain alongside their still-captured companions. Dolphins call out to each other by name when separated and orcas usually stay with their families their entire lives. Some males have been known to fall in to depressive states and even die following the deaths of their mothers. Mothers seem to show a similar devotion to their young, one seen carrying her deceased calf on the water’s surface for hours. These types of actions have little or no survival value, indicating a different driving force— emotion, perhaps even love.
In light of these revelations, human society is starting to view these impressive creatures differently. Legislators in California are attempting to ban the captivity and commercial use of orcas, and in India, dolphins have been labeled non-human persons with their own set of rights.
Persons or not, it’s clear that toothed whales are capable of much more than simple circus tricks. The extent of these capabilities, we may never know. Short of leaping in to the mind of a whale, it will be difficult to ever fully understand the intellectual and emotional complexities of these organisms—but treating them with the respect they deserve is a great first step.
Leanne Louie is a writer and biology student at McGill University. Read more of her work at http://leannelouie.com.