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.


  1. Justin Gregg (@justindgregg) · September 12, 2013

    Thanks for getting to the bottom of this David. I just wanted to point out that at the time Dr. Marino and Dr. Parsons made those comments, neither had consulted with me to determine if I was accurately portrayed in those news items. Nor, I believe, had either read the book or any of my blog posts about the book. If they had, they would have seen that I agree with the points they are making concerning the science of dolphin cognition. And I could have explained about the nature of the misquotations. The only thing I would point out is that one of the issues I address in the book is the belief that dolphins have a sophisticated ability to control their emotions due to their (emotional) intelligence, and that this has resulted in dolphins being an unusually peaceful species. This is a popular argument that has been made for many decades and is still being made today. So when I discuss the issue of peaceful dolphins in the book as one of the many aspects of intelligence, it is as a means of addressing this particular idea. I, of course, do not argue that animals that show aggression are ‘dumb’ – this would be completely nonsensical.

  2. Lori Marino · September 12, 2013

    Thank you, Justin, for your efforts to inform readers about the real content of your statements.
    I applaud you. However, I did read your blog and since the articles were quoting you I saw no reason to not take those statements at face value. I agree with you that we need to unburden dolphins from the mythology heaped upon them by our own species for thousands of years and into modern times (dolphin assisted therapy, etc.).

    With that said, I think part of the misunderstanding comes from the title of your book. You claim that the focus of your book was to show that many other animals possess sophisticated capacities that we seem to attribute only to humans and a few special species, like dolphins and apes. Fine. But might I suggest that if the title was something more like “Are Chickens As Dumb as People Think They are?” or even “What do chickens and dolphins have in common – More than you know!” the sense would have been that you were not trying to talk about the lack of intelligence in dolphins so much as the presence of intelligence in chickens and other species. Instead, you chose to make your point about other species through the lens of critiquing the science of dolphin intelligence and this seems to be a rather indirect way to achieve your stated goal. Bottom line is that the title of your book does not point to your attempting to show intelligence in many other animals. Rather, it clearly questions the intelligence of dolphins. It is a reasonable conclusion, therefore, that the book be about dolphins not being that smart. No guesswork required.

  3. Chris Parsons · September 12, 2013

    I knew that Justin had been badly misquoted and was providing his own words for this article, so my comments were on how the press were portraying dolphins – stupid and violent, so I’m sorry if I come across as criticizing the book content (which I’m waiting for Amazon to deliver and haven’t read as yet).

    As someone who has studied animal behavior for a couple of decades, I completely agree that many other non-dolphin, non-ape species show very sophisticated and arguably intelligent behaviors. Many bird species, cephalopods, canids, squirrels, have all shown abilities to solve complex problems. The more one studies animal behavior the more one discovers how much we didn’t know, and the more complex the behavior of many animals is. Dolphins do stand out at the moment because of the linguistic studies. But I wouldn’t be surprised to find out in a few years time that, for example, several bird species or maybe elephants, have the ability to comprehend linguistic rules or artificial languages.

    I also agree that we shouldn’t necessarily compare species to gauge intelligence. Something that is an important cognitive function for humans is not necessarily important for another animal. Where I might quibble with Justin is where is say’s he defines “intelligence” as how closely it resembles the actions of an adult human – I would have have called this “human-like” or “anthropocentric intelligence” to clarify (but the book may have done this, and I haven’t read it). Different species have different sensory worlds (fish may transmit complex information via their lateral lines for all we know) and different needs in order to survive these worlds, as Justin alludes to. If we are to gauge intelligence in purely human terms and a human’s it is a little like gauging the locomotion of a fish by measuring it’s ability to ride a bicycle.

    As an final aside, as I tell my students, the studies done on dolphins and their understanding of syntax and symbolic languages are particularly remarkable, because if you had done some of the same tests on Cantonese/Mandarin speakers, or or ancient Romans speaking Latin, they would have failed the tests the dolphins passed, because their languages are not structured in the same way as English. So would the ancient Romans have been stupid by the dolphin researchers? It’s all a matter of context….

  4. Lori Marino · September 12, 2013

    I agree with Chris Parsons and Justin Gregg that judgements about intelligence across species should not be based upon how closely it resembles human intelligence. We can try to get away from this notion but the question is whether we actually can. Can our species recognize and probe an ability which is completely absent in our own? Not sure it is possible. We may be stuck with being anthropocentric to some extent. However, I do think we can acknowledge that there are likely to be capacities in other species for which we simply do not have a “receptor” for and that these these capacities can be quite complex. Moreover, I hope we get away from the issues of smart versus dumb or even ranking animals by intelligence. The whole notion of dolphins being the second smartest animals in the world has become a caricature of the original encephalization data I published in 1998. Perhaps we can work towards describing a species’ cognitive profile with an objective laying out of what different species seem to be good at and weak at and the style of their information processing. That notion decenters the task of deciding who is smarter than whom.

  5. Mel · September 12, 2013

    Hi all,
    I’m not an expert or an animal behaviour researcher as such for that matters, but I have to say that when I read the Daily Mail article I was shocked… and I did contact the Dolphin Communication Project about this issue…
    I agree with Lori Marino that the title of your book does not reflect what your goal seems to be. And in any case, I think that chickens being not as “stupid” as we think, has little to do with dolphins being not as “smart” as we think…
    Now, reading this blog it became clearer to me the overall idea of your book (which am going to read very soon); however, I still don’t fully understand when you say that “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”… and right after you say: “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”.
    In my personal opinion, and just adding a bit more to what Lori and Chris already said, using this definition of intelligence, you’ll never be able to find a species that is “smarter” than humans, and as you say yourself, comparing between species constitutes bad science. I am guessing I need to read the book to better understand your point of view…

  6. Justin Gregg (@justindgregg) · September 12, 2013

    Dear Lori and Chris,

    Thank you for your thoughts and reactions. Indeed Chris, I agree with all of your points about ‘anthropocentric intelligence’ and the first chapter of the book is dedicated to a discussion of this issue. I also explain why I adopt that particular definition of intelligence; it is simply a means of explaining how most humans (but not necessarily scientists) relate to the idea of intelligence. But it’s a handy jumping off point for describing the scientific literature on animal cognition. Comparative cognition is a perfectly legitimate and useful scientific field of inquiry, but comparative intelligence, which often involves ‘ranking’ and usually places humans at the top, is not science. Because the book investigates all of the popular ideas of dolphin intelligence (as opposed to just what scientists would place under the umbrella of cognition), I end up adopting the above definition.

    As for the title, Are Dolphins Really Smart? is cool because it can be read in two ways: are they actually smart, or are they in fact really really smart. It’s catchy, and I don’t feel that it is implying that the answers is “no.” It is in fact a question that I receive on an almost a daily basis from students and the general public. And it is also a question that inspired me and many other researchers to undertake a career in the sciences to begin with.

    By the way, I also just got an email from the Daily Mail corrections department. They are going to change some of the misquotations and other incorrect info in their article. So that’s nice to hear!

  7. tim ecott · September 12, 2013

    Once again: the worlds of science and journalism collide. I have read the Gregg book. What is remarkable about it, is that here you have a scientist who happens to know a lot about dolphins, especially their ability to communicate. With proper rigour he has analysed the many claims made in both science and popular literature about dolphins in order to clarify the sometimes hysterical nature of the claims made on their behalf. Given the current scientific and ethical debate about whether ‘non-human persons’ like cetaceans should be given legal recognition of their higher cognitive status – this seems like an important contribution to the debate, and to the body of literature on marine mammals and our relationship to them. Unfortunately (speaking as an author, naturalist and journalist) what I learn from the correspondence here on SSF is that journalists and scientists should remember that without reading a book it is dangerous to pass judgement. And herein lies the dilemma: if you want publicity you talk to journalists. If you want scientific opinion you confine yourself to peer-reviewed journals and papers. Scientists are (in my view) too often wary of entering the mainstream ‘popular’ arena for fear of being mocked or misunderstood by their colleagues. Gregg has proved that it is not just communication between humans and dolphins that is difficult. Perhaps he could write a series: Are scientists really smart? and Are journalists really dumb?

  8. Drew Scerbo · September 14, 2013

    My main opposition to this book (that I have read portions of online thanks to book ‘previews’) is that there are shameful marketing ploys being used to promote it. Whether it’s the provocative title, the media that surrounds the public’s reaction to the title or even the author’s choice of excerpt/talking points; its disappointing that there is an inherent lack of honesty in those promotions. I cannot “prove” that this was intentional, but I have significant evidence to think so. Unfortunately, this has become the “norm” in our society.

    Now, I have no opposition to people earning a fair wage for the work that they do. It requires exemplary dedication and skills to produce a volume and take it to publishing. What I do object to is the need to sell books based upon title(s) rather than the content. Had this book been entitled something other than “Are Dolphins Really Smart”, I may have purchased this book.

    There is a pattern forming on the “Best Seller” lists where the title has to sell the book far more than the content. Why else do we see recurring volumes of “7 Weeks to Rock-hard Abs” top the charts when the content is nearly identical to the previous edition? The title usually only differs in a reduction in time period. Likewise, publisher’s and authors (either separately or in unison) try to create drama by acting upon people’s emotions. This patheitc attempt to garner free press coverage turns my stomach.

    I fully plan to read the book (in entirety) at some point, but due to promotion tactics, I’ll happily wait until a used edition or a friend’s hand-me-down brings it into my possession. As I mentioned, I also read a good portion of the book in the free samples sections on certain retailer sites. I liked some of what I read even if I didn;t agree with all of it. Still, I cannot get past the ridiculously misleading title. It’s like putting a “100% NO CHOLESTEROL!” sticker on a tomato. I know that supposedly “all is fair in war and publicity”, but I will not participate in duping the public into purchases. The content should have been able to speak for itself.

    Dr. Gregg does very good work with the Dolphin Communication Project; I respect him as a researcher and scientist. I do not, however, think the title is “cool”…I believe it’s meant to create controversy, stir up outrage and ultimately sell books for money. While $9.99 – $19.99 is not an extravagant sum, I’ll hold on to mine.

    Cheers to all,


  9. Last week I wrote an article for my paper, The Sunday Times, London, about Justin’s interesting new book Are Dolphins Really Smart? (

    Justin was very helpful in initial interviews. My science articles are almost always read back to the relevant scientists before publication and that is what happened in this case. A draft of the final news article was read back to him before publication, after which the few changes he requested were incorporated. I hope we were both pleased!

    Unfortunately, one of our leader writers, Roland White, then used my article as the basis for a light-hearted leader column. In that leader column he attributed views to Justin that he (Justin) had not actually expressed. This was because of a misreading of my article and was clearly a (well-intended) mistake.

    Roland has since contacted Justin directly to apologise. This Sunday we will publish a letter from Justin making clear his real views.

    So, our apologies to Justin for what happened. We usually do better than this and I hope we have gone some way to putting it right.

    Perhaps the most interesting lesson from all this is how much people care about dolphins!

  10. Jason Bruck · October 5, 2013

    As a dolphin researcher who has dealt with press recently I sympathize with Justin. When my work on dolphin social memory was released I took great pains to say we don’t know what social memory really looks like in other species. That, however, did not stop media outlets from reporting in big bold headlines that dolphins had better memory than elephants. Even as I was quoted in those same articles saying that this may not be the case.

    I think we need to ask, is the oversimplification performed by the media with regard to science necessary, as it leads to more confusion in the public? I just heard Justin’s work completely misquoted on NPR’s “Wait Wait Don’t Tell Me” and while I wish Justin success with his book it is hard for us scientists to out-megaphone large media outlets when they get our work wrong.

  11. Russell Hockins · October 8, 2013

    I have my own views of their intelligence having participated in three different interspecies communications projects including Lilly’s JANUS in the mid 1980’s and had many up close and hands-on personal encounters with many Cetaceans including four Orcas without having to be a trainer or go through any special training for it.

    The acceptance of another species on the planet, one that has been around *much* longer in their current from and level of evolution than Humans and that has an intelligence that, in their own way, is IMHO different but still equal to Human intelligence is not something that Human society can readily accept as it throws much of what is currently believed, i.e. Humans are the top and only intelligence on the planet, into question. The social and religious ramifications are far reaching and are not easily accepted by the masses.

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