How do we define human intelligence? IQ tests miss something that uniquely defines what we consider “intelligent” creatures: personality. While an IQ test may be able to gauge whether or not you have the insight enough to uncover a complex pattern or solve a difficult math problem, it cannot predict your social decisions or your level of ability in social interactions.
Dolphins, much like humans, are very social creatures. Richard Leakey previously studied dolphin intelligence, and came to the conclusion that intelligence is primarily defined by the social complexity of a being. That is, are the animals able to communicate through various emotive means, whether the social interaction is one of foraging, protecting, playing, or learning? Dolphins have a great capacity of learning from one another; it is often the case that one dolphin can be taught a complex behavior and easily teach it to another without the trainer’s help. The ability to recognize a new behavior, isolate its environmental conditions and perform it perfectly without having to be taught by the trainer that requested the behavior is quite astounding.
Dolphins group hunt, creating “bubbles” in the wild, where they work together to pool schools of fish into one area and then take turns alternating between guarding the bubble’s integrity and nabbing a fish for themselves. The ability to communicate successfully allows them to not only trap prey, but also to keep the prey at bay so that feeding time doesn’t become a free-for-all. While sheer brain mass may be an indicator of intelligence, it is not always true that larger brains mean higher thinking. What must be considered is the encephalization quotient of an animal, or the relative size of the brain to the rest of the body. Our EQ is two times that of a dolphin, although a dolphin has a larger surface area due to complex infoldings of the cerebral tissue. This surface area essentially allows for neural function; the greater the area, the higher the function. That’s not to say that humans are smarter than dolphins or vice versa.
In fact, we shouldn’t think about it in terms of “smarter than” because our worlds are vastly different. Take, for example, a New Yorker out of New York and drop them off in a jungle somewhere. Chances are they won’t last long without some help from the locals. Now, take someone from that same jungle and plop them down in New York. Again, they won’t find themselves having an easy time without the help of a person that understands their surroundings intimately. It is believed that the higher cerebral surface area in dolphins is crucial to the variance in environment from us. While we live in a world where we generally walk on two feet on flat surfaces to get places, dolphins utilize their 3-D surroundings to the greatest degree. They don’t just simply swim in straight lines or take underwater sidewalks to where they want to go: they have to be able to navigate in a highly variant environment.
Specifically, it’s the neocortex that’s larger in dolphins; this part of the brain makes up 98% of the cortex in dolphins and only 67% in humans. The neocortex is responsible for creativity and imagination, two crucial pieces to flexibility in a marine environment. The cerebellum in dolphins is larger relative to the rest of the brain than in humans. This is the central location for cognition and motor control, yet another crucial aspect of agile swimming. We often think of dolphins as having very acute senses due to their abilities to respond quickly to various stimuli. However, the visual centers of dolphins are actually less developed than in humans. Dolphins exhibit monoscopic vision, meaning that they can focus their eyes on different objects at the same time. However, while they can focus their left eye on one thing and the right on another, they are not capable of stereoscopic vision as exhibited in humans. They cannot focus in on one object with both eyes unless they are looking directly below them. Therefore, it is crucial to have some other mechanism by which to gauge distance from objects, their size, material, etc. It is the auditory center that gives dolphins such acuity in movement and awareness of surroundings. A dolphin’s ears are mere pinprick-sized holes on either side of the head. However, their ability to echolocate is actually what gives them such skill in movement without the use of vision. Clicks are sent out through the melon (area in the head) which focuses the clicks (acts as a kind of lens, so to speak). Lower frequency clicks allow the dolphin to gain a general sense of their surroundings, while higher frequencies allow for focusing in further on an object. Clicks are made every 50-120 milliseconds. The echo from an object bounces back and is registered in the hollow bones of the jaw and some fatty tissue surrounding the ears. This allows them to gauge not only where an object is spatially, but also its exact shape, and even density. Dolphins can echolocate anything from a rock to surgical pins from a fractured hip. They’re that good. In fact, they’re even able to teach each other behaviors without any visual aid.
A dolphin trained a behavior in a separate room can communicate with the untrained dolphin in the next pool without any visual cues how to perform the behavior. And the untrained dolphin will do it perfectly. Dolphins also often mimic behavior, both in humans and other dolphins. These behaviors have been noted to be as simple as a calf mimicking its mother’s breaching (jumping out of the water, usually because they’re upset) to a calf that, upon observing a man blowing smoke rings with a cigar, went to its mother to acquire milk and came back to the man to show him her milk rings she then blew into the water.
Now that your mind’s blown, we’ll go right in that direction: blowholes! Despite general belief, dolphins don’t have vocal chords. They produce all the sounds they make through nasal sacs and sinus passages. Sounds are made through the blowhole, not the mouth, although the mouth may open and move in order to alter pitch of a sound. The blowhole is used for breathing; dolphins do not breathe through their mouth ever. In fact, their throat remains closed off unless receiving food and acts kind of like a sphincter muscle to prevent water from going in. When a dolphin breathes, it always exhales before it inhales in order to blow out any water that may be resting on top of the hole. Dolphins communicate through whistles and clicks, heard through the blowhole.
Dolphins have signature whistles that allow other dolphins to identify them, which is useful when communicating information to other dolphins (in case they want to trash talk, which believe me, they do) and to keep track of genetic relationships to prevent inbreeding. Signature whistles are used much like we use names and can be altered depending on the situation at hand. For example, consider how a child says “Mom” when they’re asking a question. Now consider how that same word sounds when the child is terrified of something. The same idea applies for dolphins; trainers will often see mothers suddenly take off to attend to a calf that seems fine, and yet it has changed the signature whistle to say, “I’m hungry” or “I’m stuck”. This seems to be the primary way that dolphins communicate emotions, as well as through body language. However, unlike humans, dolphins cannot change their facial expression. Their “happiness” is rather perpetual, as their jawlines tend to slant slightly upward to give the appearance of a smile. As humans, it’s ingrained into us that this facial expression should be associated with joy, complacency, satisfaction, and yet in dolphins it cannot be used as a signal for emotion.
I asked a question today that I thought might be received with odd looks, “Aside from the fact that dolphins have no limbs, what prevents them from being terrestrial mammals?” Actually, the answer is quite interesting. For one matter, dolphins can’t echolocate in air, the must have the water medium in order to do so. For another, water is much denser than air. So? Well, because these mammals are adapted for water, so are their internal organs. When placed on land for long periods of time, dolphins experience internal bruising due to the increased “weight” that they experience relative to their weight experienced in water (think how fast you fall in air versus water). Another thing to consider is body temperature. Dolphins, like all mammals, are warm-blooded and so maintain a regular body temperature, theirs being 96.8 degrees Fahrenheit. Water happens to have a much higher heat capacity than air, and so body temperature regulation is adapted for water, and would change in air. One thing that doesn’t occur, however, is desiccation. Dolphins don’t “dry out”. So there you have, a general set of reasons for why they haven’t yet taken over the world.
Unfortunately, I won’t be able to post photos or videos until I go home, as the camera simply does not like the cord I have for transferring said photos and videos. I promise to upload them as soon as I arrive back to the Tundra.
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