Book review: are dolphins really smart?

melMel Cosentino obtained her Degree in Environmental Biology at the Universidad de Málaga (Spain) and her MRes in Applied Marine and Fisheries Ecology at the University of Aberdeen (UK). She has been involved in cetacean research since 1998, starting as a volunteer for Fundación Orca Patagonia-Antártida in Argentina (her country of birth) working in educational campaigns against killer whale captivity. Since then she has participated in several research projects in Spain, Portugal and Norway.  Mel has conducted field work, both from land and at sea, focused on different cetacean species, including killer whales, Risso’s dolphins and Northern bottlenose whales. In addition, she participated in the Annual meeting of the IWC as part of the Luxembourgish delegation, both in 2011 and 2012.


“The fact that an opinion has been widely held is no evidence whatsoever that it is not utterly absurd; indeed in view of the silliness of the majority of mankind, a widespread belief is more likely to be foolish than sensible” (Bertrand Russell)

gregg bookThis is how the book “Are dolphins really smart?” by Dr. Justin Gregg starts. It has been recently published and it is available in several countries, including the US and the UK. Moreover there have been a large number of newspaper and web stories based on the conclusions of the book, most along the lines of “dolphins are no smarter than chickens” “Flipper is a thug!” and “dolphins are dumb” This led to a rebuttal article published in Southern Fried Science when David Shiffman interviewed the author and some cetacean scientists about the media frenzy spawned by the book’s release. Studying animal cognition is no easy task, and Dr. Gregg has put together a great amount of information; however, I believe the reader will be confused and misled by some of the comments and statements made by the author, a scientist who holds a PhD and who claims to be analysing the evidence “as impartially as possible with a sincere desire to let objectivity take centre stage”.

It would be impossible to critique the thesis of the book point by point, so I have compiled the topics I consider to be more problematic.

Cognition and intelligence

Although the author uses the following – arguably an extremely anthropocentric – definition of intelligence “It is a measure of how closely a thing’s behaviour resembles the behaviour of an adult human”, he provides a comprehensive explanation of the difference between cognition and intelligence. The comparison is in fact a common practice, and the basis for scientific studies on animal cognition. A direct comparison, however, should not be made, as it fails to consider the evolutionary and ecological circumstances of cognitive skills evolving in cetaceans, primarily oceans are not human-like environments and therefore dolphins could have not evolved having human-like behaviours.

Dozens of biological characteristics (e.g., brain size), research experiments and opportunistic observations are analysed in the book. The methodology is simple: humans show a particular behaviour/characteristic and dolphins (and other animals) do not, or they do to a certain degree. Obviously human intelligence is assumed, but unreasonably generalised (e.g., a handful of modern humans went to the moon, thus all humans are capable of building a spacecraft, pilot it and travel out to space). The baseline he uses for the comparison will leave many animals outside the “intelligent” box, but it will also exclude the majority of the current human population, not to mention the entire history of Homo sapiens prior to the modern era of invention and technology.


When describing complex behaviours observed in the wild such as sponging by bottlenose dolphins and cooperative seal hunting by killer whales, the author claims that these behaviours are anecdotal and have no scientific value given the lack of an experimental design and the small sample size. He claims that “dumb luck, serendipity or trial and error learning” cannot be ruled out, given that researchers were not there to observe the first time the behaviour arose: “For all we know it was alien visitors who first taught capuchins [monkeys] to smash nuts and dolphins to dig for fish with sponges, so we can’t really be certain how much complex problem solving Sponging Eve(s) engaged is.” This does somewhat disregard a large number of studies both in the wild which have reported spontaneous problem solving and novel behaviors in animals, particularly the primate and elephant literature. And even after this statement, where he claims that learning (“taught”) could be the underlying cause, discarding problem solving, he then claims that social learning has not been proven in dolphins, though it has in ants. Finally the author also questions the relevance of use tool is, as there is no manufacturing involved.

Regarding emotion-driven behaviours the author explains that human behaviour might “not necessarily be the prototype against which emotion-driven behaviour be measured”, though he does not apply this criteria himself. “The so-called ‘argument –by-analogy’ approach” means that not observing certain emotion-driven behaviour (such as grief), does not mean it is not present. It is easy to see that people from different cultures show their feelings differently. When such behaviours have been described in wild animals, the author argues that it is not science, but the interpretation of the researcher.

Similarly, when discussing empathy the author provides “anecdotal” accounts such as dolphins rescuing drowning swimmers or rescuing people that are being attacked by sharks (which has reportedly occurred in many locations around the world), though arguing that this could be a genetic predisposition due to their complex social lives. But he goes even further, and reasons that a person being attacked by sharks cannot properly interpret and remember what is actually happening and therefore they are not a reliable witness.

Special creatures

Dolphins are often described as special creatures, showing “extraordinary” behaviours. But, as it happens with humans, many of these behaviours or characteristics are shared with other animal species. Dr Gregg argues that because those behaviours are “by no means unique” to dolphins, then dolphins are not “special”. For example: parrots can comprehend symbols, some insect species have complex social lives, rats seem to show empathy, bees can transmit “limitless” information about food location, jumping spiders respond to video stimuli and zebras have VEN cells. The author fails to stress that under this line of reasoning we are not special either.

Sentences in the line of “this does not tell us anything“, “dolphins are not the only animals capable of this behaviour”, etc, are abundant. For example, dolphins are capable of remembering learned behaviours for life, as well as arbitrary associations between symbols and their referents, to which the author responds saying there is not much to “chew on” as it has not been tested for how long and how many of those associations dolphins can actually remember.

It is the presence of all of those many cognitive behaviours and characteristics that dolphins share with humans (and not each separately) that arguably make dolphins “special” creatures. This fact gets lost along the way when the characteristics are analysed and compared one by one, in isolation. Moreover, readers might (wrongly) assume that those animals that are being compared to dolphins are in the same cognitive level.


In the book, the validity of many scientific research experiments conducted to study dolphin cognition is simply dismissed under alternative explanations, not always all that scientific. For example, when talking about dolphins responding to degraded video images of gestural symbols, Gregg says that “it might well be that Ake simply understood the trainer as being stuck behind a window”. Similarly, he uses confusing comments after promising results: “Many people might have a gut feeling that dolphins understand pointing because they really do know what humans “want” when they point to something. But I suspect fewer would say the same about dogs, even though both species understand pointing in similar impressive ways”. However, cognition studies in other animal species are accepted without questioning, and often the interpretation is misleading. For example, the author states that chickens can plan ahead because they learn that waiting before eating food they have been offered will bring more food later on, which is actually a typical conditioning behaviour used to train many species of animals. Whereas, site fidelity and seasonal, and often unique, local specializations of prey hunting techniques shown by most dolphin populations around the world are considered to be a genetic predisposition or to have evolved due to environmental conditions, involving no planning, social learning or cognitive problem-solving.


My biggest concern when reading the book was the many subjective comments made by the author, especially when he claimed he was going to be objective. A lay person can easily believe his statements are facts: “Whether we begrudge him or embrace him, no dolphin scientist can deny that the current body of literature on the subject of dolphin cognition is balanced firmly (if at times precariously) on the shoulders of John Lilly”. After he previously described Lilly as basically a drug-user pseudo-scientist obsessed with dolphin intelligence, this comment effectively discredits every dolphin cognition researcher that has existed over the last 50 years.

Another example of unfortunate comments is made when discussing dolphin’s aggressive behaviours. Some people claim that dolphins have a special bond with humans and that they live in harmony with their environment. We know dolphins are often “friendly” (or let’s better say “usually not hostile”, or to quote Douglas Adams “mostly harmless”) towards humans. And we can fairly safely say that dolphins as a group (there are almost 40 species of dolphins worldwide) do not cause mass destruction of their environment, chemical and sound pollution, have not engaged in vast programs genocide or marine world wars (at least that we are aware of). However, there are reports of aggressive behaviours within and between species, such as bottlenose dolphins killing harbour porpoises without a predatory purpose. Also, several humans have been attacked by dolphins, both in captivity and in the wild.

Obviously intelligence is not related to aggressiveness, even the author recognises this. Humans are supposed to be the most intelligent animals on Earth and yet behave poorly in countless occasions, even when there are good intensions behind those behaviours. So it truly shocked me to read the following comment: “Finally, it goes without saying that the many species of aquatic animals that dolphins hunt, kill, and consume as food (e.g., mackerel, seals, grey whale calves) would, if allowed to chime in on the question of harmony, forcefully argue that dolphins can be fairly nasty individuals. There are, after all, no vegetarian dolphins”. Clearly this statement is unquestionably subjective and might lead the reader to think that dolphins are nasty because they are not vegetarians. I have problems understanding the rationale of such comment. And where does that leave the meat-eating humans? Or the many human populations that survive through hunting?

And the list goes on… but I’ll stop here…

The overall conclusion of the book can be summarised as follow: “Thus, unless we discover that dolphins are building launch pads under the waves ready to send dolphin-astronauts into near-earth orbit, we will probably never reach a stage when we should consider dolphin intelligence as rivalling the intellectual abilities of an adult human”.

This is not a scientific conclusion, but just the mere opinion of the author. What is more problematic is the fact that only a small minority of humans have actually been able to build launch pads and send astronauts out to space. This is anecdotal. Most human nations on the planet have not sent rockets into space with human passengers. The vast majority of humans are not even close to being able to build launch pads, or cars, or kitchen tables for that matter. Not to mention small isolated human communities such as some tribes in Africa or the Amazon rainforest that have, literally, never seen an airplane in their lives. Moreover, humans were only able to achieve these feats in the past half century or so. The majority of the history of Homo sapiens is a species that could use only rudimentary tools such as sticks and stones, no more complex than the tools used by chimpanzees, capuchin monkeys, dolphins, sea otters or several bird species.

The author explains, at the very end of the book, that one of the aims of the publication was “to determine if the scientific evidence of dolphin intelligence was strong enough to form the basis for both legal and philosophical arguments for personhood in dolphins”. One of the consequences of declaring dolphins non-human persons is the end of captivity, since it would be considered slavery. Dr Gregg is the co-editor of Aquatic Mammals, a journal funded by the International Marine Animal Trainer’s Association and he himself works with cetaceans in captivity during a period in American history when the ethical and moral justification for holding highly cognitive species, such as cetaceans (but also primates, elephants and other species) are receiving much greater public and official scrutiny. I question his objectivity.

January 29, 2014 • 3:10 pm