There were no similar sessions devoted to extending the rights of chickens. But perhaps there should have been. Like dolphins, chickens can identify and remember individual members of their social groups, are capable of social learning, and communicate using a complex set of vocalizations—all traits that have been cited as evidence of dolphins’ superior smarts and sophistication.

Many of our cherished beliefs about dolphins are not supported by scientific evidence, says one researcher.

In recent years, there’s even been a movement to redefine dolphins as more than mere animals. At its 2012 conference, the American Association for the Advancement of Science featured a session in which scholars, ethicists, and conservationists made the case that dolphins have such clever minds and rich emotional lives that we should designate them as “nonhuman persons” and dramatically expand their rights.

At times, the dolphin can seem more like a symbol than a living, breathing being. Social, playful, and photogenic, dolphins have come to represent intelligence, empathy, and peace—and all that is good and right in the world. So strong is their cultural cachet that it can prompt us humans to do utterly bizarre things; last year, a young couple made the news when they flew to Hawaii for a “dolphin-assisted birth.”


Such findings suggest it may be time to abandon the assumption that there’s something special about dolphins, Justin Gregg argues in a new book, “Are Dolphins Really Smart? The Mammal Behind the Myth.” Gregg, a psychologist who wrote his dissertation on dolphin echolocation and social cognition and now conducts research as part of the Dolphin Communication Project, wants to debunk the myths that have grown up around the cetaceans.

Many of our cherished beliefs about dolphins, he points out, are not supported by scientific evidence. The whistles dolphins use to communicate are diverse and varied, but they don’t technically qualify as “language.” Dolphins may use tools, but there is not yet proof that they actively manufacture them, as crows and chimpanzees clearly can. And evidence that dolphins are capable of complex emotions, such as empathy, is inconclusive.

Researchers are documenting surprisingly complex behaviors in all sorts of creatures, from chickens to fish. AFP/Getty Images

“I can safely state that the notion that dolphins are smart and chickens are stupid is at best a gross oversimplification and at worst completely wrong and thoroughly unhelpful,” Gregg writes.

Our cultural devotion to dolphins runs deep, and since it was first published in the United Kingdom last fall, Gregg’s book has roused some dolphin defenders. (“The book angered me so much I nearly threw it out mid-read,” wrote one displeased Amazon reviewer and self-described “cetacean enthusiast.”) But Gregg is not arguing that dolphins are dumb: Rather, he’s trying to persuade people that by singling out dolphins, we are missing something important about the rest of the animal kingdom. Researchers are increasingly documenting surprisingly complex behaviors in all sorts of creatures, from chickens to fish, he points out—enough that we need to stop thinking so simply about what “intelligence” means.


Gregg spoke with Ideas by phone from his office in Eindhoven, in the Netherlands.

IDEAS: There’s been a bit of a backlash to your book by people who think you’re calling dolphins dumb. Why do you think people are so sentimental about dolphins?

GREGG: People have been passionate about dolphins for a really long time. I mean, there are stories from antiquity about the human-dolphin relationship, and ideas that it was illegal to kill dolphins in Ancient Greece....The problem, of course, is that since the public really likes dolphins, if it looks like I’m doing anything that even smacks of trying to take them down a peg by saying they’re not that smart, then people just don’t like that. That wouldn’t have happened if I was writing a book about squid intelligence, or meerkat intelligence.

IDEAS: Is there a particular dolphin trait or skill that you think has been especially overhyped?

GREGG: You hear a lot of things, really simplistic statements along the lines of, “Well, we know dolphins have their own language.” And that’s a statement that should be qualified.


IDEAS: What’s the difference between what dolphins are doing and what linguists would call “language”?

“In an ideal world, we stop using the word “intelligence” and we just talk about cognition,” says Justin Gregg.

GREGG: We can essentially, using human language, talk about any subject that we can think of. It’s limitless in its ability to discuss subject matter. Whereas most animal communication signals are limited to a few kinds of information, usually representing their emotional states or possibly their intentions. But humans can talk about anything—abstract ideas, concrete ideas—you name it and we can discuss it.

IDEAS: Another pervasive belief about dolphins is that they are these friendly, gentle beasts that live in total harmony with each other and with other creatures.

GREGG: There are some folks who believe that they really are supernaturally friendly and never violent at all and would never hurt a human or another dolphin. And that’s, not surprisingly, not true. They’re just as capable of being aggressive as any complicated social mammal, like humans or chimpanzees or dogs.

IDEAS: If we give dolphins too much credit, what about the other side of the coin? Can you give me an example of a species that has cognitive skills that are underappreciated?

GREGG: I think it would be nearly any species, really. The problem with trying to rank species and saying “Well, dolphins or chimpanzees are the smartest,” and then you get a ladder of intelligence, and then you get down to reptiles and those sorts of things—that’s just a really bad way to think about how animals think. And a lot of the time you have, therefore, prejudice. In terms of, well, dolphins do something like use tools so that fits into our ideas of dolphins being smart. Which is fine, but then we ignore things when we see, for example, crabs using tools or [an] octopus using tools.


IDEAS: What’s a better way to think about animal intelligence?

GREGG: In an ideal world, we stop using the word “intelligence” and we just talk about cognition. Cognition is just the things that brains do—information processing leading to behavior. And so we can talk about all the things that, for example, a squid can do in its own little squiddy world, all its kinds of behaviors and the way it thinks about and perceives the world, and then you just get a big long list of squid stuff happening.

IDEAS: What else do we need to learn about dolphin behavior and cognition? What are some of the big outstanding mysteries?

GREGG: I think the most promising thing at the moment is understanding their social cognition. Because it seems like the kind of intelligence that we see in dolphins, or the things that they do that make them similar to humans, is really based on their social cognition, so the way that they evolved to live in these complex groups and deal with the ever-changing societies that they live in and these relationships that they have. So there’s great research coming out of Shark Bay, Australia, for example, or Sarasota, where people are tracking long term these dolphin relationships, and I think that’s really the way forward, to understand how their behavior evolved within the context of their social world.


IDEAS: What do you hope that readers take away from your book?

GREGG: I hope that people will get rid of these ideas of there being that continuum of intelligence with dolphins at the top, and just appreciate all the different species for what it is that they can do, without feeling the need to compare them to humans or to dolphins or chimpanzees.

IDEAS: Finally, for the record: You are not calling dolphins dumb?

GREGG: Absolutely not. I’d say that they are very intelligent, but then of course, it’s really hard to define what intelligence is. That’s the big caveat.

Emily Anthes is a science writer and the author of “Frankenstein’s Cat: Cuddling Up to Biotech’s Brave New Beasts.”