Why dolphins are even cleverer than we thought

Who you calling stupid? Unfortunately, humans have yet to decode dolphin speech.

Are we as unique as we like to think? According to a major new study, dolphins and whales have a comparable intelligence to us. This flies against centuries-old beliefs about human nature.

“So long, and thanks for all the fish.”

This is the message that dolphins leave for humans before beaming into another dimension in Douglas Adams’s comic series The Hitchhiker’s Guide to the Galaxy. Scientists have long attested the intelligence of dolphins; Adams liked to joke that they are even smarter than humans.

According to new research, this may not be far from the truth. Researchers studying cetaceans — a group which includes dolphins and whales — have found that their social skills are more sophisticated than previously thought. The evidence suggests that, as with humans, their socialising is linked to their large brains.

It turns out that the animals call each other by a kind of naming system. More than that: they gossip. They also look after friends’ offspring, teach their young to hunt, help humans catch fish, and much more. This amounts to a “culture” not unlike ours. The only thing that stops them from building cities, says one researcher, is that “They didn't evolve opposable thumbs.”

This kind of finding may be striking, but it is increasingly common. For centuries, humans saw themselves as uniquely complex and intelligent. By contrast, animals seemed primitive, barely conscious. “Animals are mere machines but man stands alone,” noted the 17th-century philosopher René Descartes.

Two hundred years later, Charles Darwin pushed back against this belief, noting that all differences between animal and man are “of degree, not kind”. By the mid-20th century, zoologists were finding evidence that animals share human traits like language and morality.

Much of this research has focused on other primates — our closest relatives. Primatologists have shown that monkeys and chimpanzees have a rich emotional life and an advanced approach to using tools. But the field of “animal cognition” is growing fast, yielding such eye-catching headlines as “Chickens might be evil” and “Your cat can grasp some basic laws of physics”.

And now scientists are implying that dolphins are basically thumbless humans. Is it time we stopped bigging ourselves up so much?

Man versus beast

“Indeed,” say some. We are still the most sophisticated species on the planet. But it is becoming clear that supposedly unique human characteristics are actually common in the animal kingdom. This makes sense: after all, we all share the same ancestors. We are not in a league of our own.

“Rubbish,” reply others. Take this new study: no other species would be capable of the collaborative effort, abstract reasoning and mastery of technology that made it possible. There is a reason we are studying dolphins and not vice versa. We have attained a whole other level of consciousness.

You Decide

  1. Does it make sense to compare the intelligence of species?
  2. Given this new research, should we change our relationship with dolphins?


  1. List the five words that you most closely associate with “intelligent”. Then tally up everyone’s answers in the class. Which words came up most frequently?
  2. Write a short story from the perspective of a dolphin which decides to study humans. You can be humorous or serious, but try to imagine what the dolphin’s conclusions would be.

Some People Say...

“There’s nothing funnier than the human animal.”

Walt Disney

What do you think?

Q & A

What do we know?
An adult human brain weighs around 1.4kg — roughly the same as a dolphin’s. But the honour of the world’s biggest brains goes to sperm whales; their brains come in at 8kg. But when you look at the ratio of brain size to overall body mass, the rankings change. By this calculation, humans and dolphins have a relative abundance of grey matter.
What do we not know?
Why some species have larger brains than others. As we cannot recreate millions of years of evolution in a lab, we will never know for sure. So we form theories instead. One of the most popular is the “social brain hypothesis”: the idea that species which form large social networks need more brainpower to keep track of all those relationships. The findings of this new study seem to be consistent with the hypothesis.

Word Watch

Douglas Adams
(1952-2001) An English writer known for his satirical, wildly funny works of fantasy. He was also a passionate animal rights activist — he once climbed Mount Kilimanjaro in a rhino suit!
New research
The study was a review of existing research on 90 kinds of cetacean. It was published in the journal Nature Ecology & Evolution.
The researchers found that dolphins address each other with “whistles” unique to each individual. Sometimes they whistle about a dolphin which is not present.
In this sense, “culture” refers to knowledge and habits that are passed down the generations within a social group.
Opposable thumbs
Most primates (including humans), as well as some other species, can touch their fingers with their thumbs. This allows us to grasp things easily, giving us a huge advantage when eating or using tools. Some primates also have opposable toes, which are useful for climbing trees.
Chimps (which are distinct from monkeys) share around 99% of their DNA with humans, making them our closest relatives.

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