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Dolphin intelligence researcher did not say that dolphins aren’t intelligent as Daily Mail, Sunday Times claim


A screen capture of the Daily Mail's headline for this article

A screen capture of the Daily Mail’s article headline

Earlier this week, the Daily Mail ran an article which claimed that dolphins are not as intelligent as is commonly believed. The crux of this provocative argument comes from an interview with Dr. Justin Gregg, a research associate with the dolphin communication project who studies social cognition.

According to the Daily Mail article, Justin Gregg said, “Dolphins are fascinating in their own right, but in terms of intelligence they are nowhere near as special as they have been portrayed…they are less sophisticated than chickens.” In an editorial that was likely the source of the Daily Mail article, the Sunday Times claims that he said “Not only are dolphins dimmer than the average chicken, says Justin Gregg, a zoologist, but they are also capable of gang rape and acts of violence. So don’t be taken in by those winning smiles.”

Unsurprisingly, this article has ruffled some feathers in the marine mammal researcher community.

Lori Marino, a marine mammal researcher and Executive Director of the Kimmela Center for Animal Advocacy, notes that “readers should not confuse aggressiveness with intelligence. Humans are very intelligent and also very aggressive. Dolphins are very intelligent and they can also be aggressive. The two have absolutely nothing to do with each other.”

Professor Chris Parsons, a dolphin researcher and author of the textbook “Marine Mammal Biology and Conservation,” made a similar point:

“Dolphins are not the mystical, serene creatures that some would like to believe. They can be very aggressive. Personally I’ve been quite seriously bitten by a dolphin. Many dolphin trainers and members of the public who have tried to swim with dolphins have been injured. The largest of the dolphins, the killer whale, have killed four trainers at aquariums/marine theme parks and injured dozens and dozens of others (see the 2012 article “killer whale killers” in  the journal Tourism in Marine Environments 8(3) ). But a capacity for violence does not make something stupid. Chimpanzees one of our nearest non-human animal relatives have been reported making weapons and attacking, even killing other species of primates, including attacking members of other chimpanzee troops. The most violent and destructive of the great apes are of course humans”

Dr. Parsons says that despite this violence,

“there is no doubt that certain species of dolphins have high levels of linguistic understanding, being able to comprehend sign languages and symbolic characters standing for actions and items (basically written language), complex linguistic rules such as syntax, being able to analyze how other individuals view the environment, able to ‘lie’ for their own benefit, and able to recognize themselves in mirrors – something that human toddlers are unable to do. In fact they display levels of cognitive understanding and awareness equivalent to a human kindergartener. Their cognitive abilities have been established by scientific research and the results published in peer-reviewed scientific journals. Many marine theme parks are responsible for trying to tailor public perceptions of dolphins though – they want us to think they are special, tame and friendly, as tourists fork over hundreds of dollars to feed them, swim with them or watch them do tricks, but they don’t want you to think that they are so intelligent that  visitors start feeling moral and ethical concern about having intelligent animals in a small enclosures, with little to occupy themselves beyond repetitive shows, and few freedoms.”

Lori Marino also issued the following statement:

“As a marine mammal scientist I find it unfortunate that the author of this book is encouraging conclusions about dolphins that are unmerited and has chosen to hang those conclusions on the denigration of decades of important peer-reviewed scientific research. One should always be wary of exaggerated claims such as the statement that dolphins are dumb. This conclusion is just as unsupported and erroneous as claims about dolphins having special healing and spiritual powers. These kinds of headlines sell books but are not accurate and no scientist of any merit would make such a claim….

Finally, the fact that other species share some aspects of intelligence with dolphins has no bearing whatsoever on the validity of claims that dolphins are intelligent. These are orthogonal issues. That would be like making the logical error of concluding humans are dumb because other species share some of our cognitive characteristics. Dolphins are not gods nor are they dumb – and both claims are irrational. “

For his part, Justin Gregg claims that he was seriously misquoted. A quick Google search of the phrase “dolphin rape,” a phrase attributed to him by the Sunday Times editorial, turns up a blog post by Gregg arguing against the use of this term. In an e-mail interview with me, he said:


“During the interview I was quite clear that it is not the case that dolphins are ‘dumber’ or ‘less sophisticated’ than chickens, or ‘dumb’ in general. When you look at the behavioral repertoire of dolphins and the results from cognition experiments involving dolphins, it’s clear that dolphins perform well on a number of metrics that people commonly associate for ‘intelligence,’ especially in the realms of symbol use and social cognition. This puts them on par with the great apes and corvids on many of these tests.

But I also point out that many species that we often consider ‘dumb’ sometimes also display behaviors and perform well on tests we associate with intelligence. Chickens, for example, have a repertoire of alarm and food calls that are sometimes considered referential signals, and have shown signs of empathy in an experimental setting. “

Dr. Justin Gregg, photo provided

Dr. Justin Gregg, photo provided

The purpose of the initial interview was to promote Gregg’s new book about dolphin intelligence, which is entitled “Are dolphins really smart? The mammal behind the myth.”  It is for sale at Amazon. In this book, he argues not that dolphins are unintelligent, but that other animals are more intelligent than commonly believed:

“”One of the main points of my book is that our common ideas of what intelligence is are often not particularly scientific, which means that making comparisons between species and trying to figure out which species is ‘smarter’ constitutes bad science….My book provides a scholarly overview of the past five decade’s worth of scientific research into dolphin cognition and behavior in order to determine if the evidence supports the claims that dolphins 1) have an unusually large and sophisticated brain that is driving their intelligence, 2) have minds that are unusually complex when it comes to self-awareness, consciousness, and emotions, 3) display unusually sophisticated behavior in the wild and in experimental situations, 4) have a communication system that is as sophisticated as human language, and 5) have unusually complex social lives, and live in peaceful harmony with each other and their environment…In the end, I find that while there is good reason to stake the claim that dolphins are intelligent animals, the science of animal cognition is a lot murkier and harder to interpret than most people realize.

There are many ways to define “intelligence,” and in the book I adopt the follow definition: Intelligence is a measure of how closely a thing’s behavior resembles the behavior of an adult human. By this definition, it does indeed seem that dolphins are intelligent. For an animal that looks nothing like a human and evolved in an aquatic environment, dolphins certainly (and maybe unexpectedly) display a lot of behaviors (e.g., complex social systems, symbol use skills, mirror self-recognition) that we usually associate with primates (mostly the great apes). Perhaps also corvids. The current body of literature on animal cognition, however, is producing findings that suggest that many other species also display these types of intelligent behaviors. It seems likely that in the coming decades we will continue to find that many species (like cephalopods and fish) display at least some of the kinds of intelligence that we currently associate with dolphins, primates, and corvids…After finishing the book I don’t think anyone will think that dolphins are dumb – they’ll probably have a newfound respect for the intelligence of dolphins and other animals, as well as an appreciation of just how hard it is to study animal minds.”

book cover

Dr. Justin Gregg was, understandably,  “a bit bummed that my first interview about the book turned into a media frenzy about dumb dolphins.” Fortunately, he received word this morning that the Sunday Times will run a correction and a letter to the editor explaining what he really said.  He also submitted a letter to the editor to the Daily Mail attempting to clarify his position.