Dolphin Intelligence

The acrobatic acts of dolphins have fascinated humans, but scientists are now more interested in how dolphins think than in what they can do. When the head researcher presses her palms together over her head, the signal to innovate, and then puts her fists together, the sign for tandem, she has instructed a pair of dolphins to show her a behaviour and to do it in unison. As they disappear below the surface, another researcher carrying a large underwater video camera with hydrophones sinks with them. He records several seconds of audible clicking beneath the waves, then the camera captures them both slowly rolling over in unison and flapping their tails simultaneously. There are two possible explanations of this remarkable behaviour. Either one dolphin is mimicking the other so quickly and precisely that the apparent coordination is only an illusion. Or when they whistle back and forth beneath the surface, they’re literally discussing a plan.

When a chimpanzee gazes at a piece of fruit or a silverback gorilla beats his chest to warn off an approaching male, it’s hard not to see a bit of ourselves in those behaviours and even to imagine what the animals might be thinking. We are, after all, great apes like them, and their intelligence often feels like a familiar version of our own. But dolphins are something truly different. They 'see' using sonar and do so with such phenomenal precision that they can tell from a hundred feet away what something is made of. They operate independently of each other. They’re a kind of alien intelligence sharing our planet – watching them may be the closest we’ll come to encountering an extra-terrestrial.

Dolphins are extraordinarily garrulous. Not only do they whistle and click, but they also emit loud broadband packets of sound called burst pulses to discipline their young and chase away sharks. Scientists listening to these sounds have long wondered what they might mean. Yet despite a half century of research, we are none the wiser. Virtually no evidence supports the existence of anything resembling a dolphin language, and scientists have been known to voice exasperation at the continued quickshot search. However, other researchers see circumstantial evidence that the problem simply hasn’t yet been looked at with the right set of tools. Only recently have high-frequency underwater audio recorders been able to capture the full spectrum of dolphin sounds. In the past couple of years, new data-mining algorithms have made possible a meaningful analysis of those recordings. Ultimately, dolphin vocalisation is either one of the greatest unsolved mysteries of science or one of its greatest blind alleys.

Why did dolphins, of all the creatures roaming land and sea, acquire such large brains? To answer that question, we must look at the fossil record. About 34 million years ago the ancestors of modern dolphins were large creatures with wolf-like teeth. Around that time, it’s theorised, a period of significant oceanic cooling shifted food supplies and created a new ecological niche, which offered dolphins opportunities and changed how they hunted. Dolphins became more communicative, more social – and probably more intelligent. Researchers have identified three levels of alliances within their large, open social network and found that two dolphins can be friends one day and foes the next. All these behaviours have the mark of intelligence. But what is intelligence really? When pressed, we often have to admit that we’re measuring how similar a species is to us. The question is not how smart are dolphins, but how are dolphins smart?