# Latest theory - dolphins are actually pretty stupid! **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [August 20, 2006, 11:38pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512 "2006-08-20T23:38:43Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Eleusis](https://avatars.discourse-cdn.com/v4/letter/e/f4b2a3/32.png) [@Eleusis](https://boards.straightdope.com/u/Eleusis)\ **Post date:** [August 22, 2006, 4:16am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/21 "2006-08-22T04:16:40Z")
[QUOTE=saoirse] Those are porpoises. [/QUOTE] Porpoises, what’s the difference? It’s all a bunch of tree hugging hippie crap! ---
**Author:** ![threemae](https://avatars.discourse-cdn.com/v4/letter/t/5f9b8f/32.png) [@threemae](https://boards.straightdope.com/u/threemae)\ **Post date:** [August 22, 2006, 4:22am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/22 "2006-08-22T04:22:50Z")
For everyone, here’s the actual article. It strikes me as relatively sound. > **[An examination of cetacean brain structure with a novel hypothesis...](https://www.cambridge.org/core/journals/biological-reviews/article/abs/an-examination-of-cetacean-brain-structure-with-a-novel-hypothesis-correlating-thermogenesis-to-the-evolution-of-a-big-brain/D50903782C73DA96065D1A33A1497C86)** > > An examination of cetacean brain structure with a novel hypothesis correlating thermogenesis to the evolution of a big brain - Volume 81 Issue 2 He isn’t flat out stating that dolphins are necessarily stupid from a behavioral perspective, just saying that our current understanding of how brain size, neural, and glial density affect intelligence doesn’t seem to support the view that dolphins are smart. “ABSTRACT This review examines aspects of cetacean brain structure related to behaviour and evolution. Major considerations include cetacean brain-body allometry, structure of the cerebral cortex, the hippocampal formation, specialisations of the cetacean brain related to vocalisations and sleep phenomenology, paleoneurology, and brain-body allometry during cetacean evolution. These data are assimilated to demonstrate that there is no neural basis for the often-asserted high intellectual abilities of cetaceans. Despite this, the cetaceans do have volumetrically large brains. A novel hypothesis regarding the evolution of large brain size in cetaceans is put forward. It is shown that a combination of an unusually high number of glial cells and unihemispheric sleep phenomenology make the cetacean brain an efficient thermogenetic organ, which is needed to counteract heat loss to the water. It is demonstrated that water temperature is the major selection pressure driving an altered scaling of brain and body size and an increased actual brain size in cetaceans. A point in the evolutionary history of cetaceans is identified as the moment in which water temperature became a significant selection pressure in cetacean brain evolution. This occured at the Archaeoceti – modern cetacean faunal transition. The size, structure and scaling of the cetacean brain continues to be shaped by water temperature in extant cetaceans. The alterations in cetacean brain structure, function and scaling, combined with the imperative of producing offspring that can withstand the rate of heat loss experienced in water, within the genetic confines of eutherian mammal reproductive constraints, provides an explanation for the evolution of the large size of the cetacean brain. These observations provide an alternative to the widely held belief of a correlation between brain size and intelligence in cetaceans.” From the conclusions: " (2) The scaling of cetacean brain mass in relation to body mass differs to that of other mammalian orders, leading to relatively large encephalisation quotients (EQ) for smaller cetaceans and relatively small EQs for larger cetaceans. Individuals of the same species show similar scaling trends of brain and body mass to that of the entire order, indicating that a similar selection pressure shapes this relationship in extant cetaceans. (3) The neuroanatomical features of the cetacean cerebral hemisphere do not indicate a structure supportive of high levels of intellectual capacities. In particular, the high glia:neuron index, the poorly differentiated neuronal morphology, the low number of neurons and cortical areas, the lack of a distinct pre-frontal cortex, the small hippocampal formation, and the altered proportions of the neuropil, will all impact negatively on the processing capacity of the cerebral cortex. (4) The vocalisations of cetaceans appear to be under the control of a specialised brainstem system of the periaqueductal grey matter, the nucleus ellipticus, which may in fact be a vocal pattern generator. This differs to the cortically based language found in humans, and argues against suggestions of cetacean linguistic and cultural abilities. (5) It is hypothesised that unihemispheric slow-wave sleep and lack of REM sleep in cetaceans functions to compensate for heat loss to the water during sleep. As significant thermogenesis is downregulated during sleep in normal mammals, this altered sleep pattern will allow thermogenesis to be maintained in both the brain (through increased glial metabolism via noradrenergic stimulation) and the body (through increased muscular movement). The restorative function of sleep can then be enabled in an aquatic environment where heat is lost approximately 90 times faster than in air. (6) It is shown that during the course of cetacean evolution there was a major punctuation in brain size, seen mainly as an increase in the size of the cerebral hemispheres. This punctuation occurred at the transition of the ancestral cetacean faunal assemblage (the archaeocetes) to the modern cetacean fauna (the Oligocene cetaceans) approximately 32 million years ago. At this transition there was a dramatic increase in both actual and relative brain size that coincided with the loss of a warm and nutrient-rich environment (the Tethys sea) and global oceanic cooling of water temperatures. Following this the size of the brain remained stable. Such a marked change in brain size does not occur in the closely related ungulates over the same time period. (7) It is demonstrated that previous proposals of the causal factors underlying large relative brain size in the smaller cetaceans do not explain the full range of observable data. Theories associating relative brain size with an increase in general levels of intelligence rely upon unproven assumptions. Vocalisations are shown to consist of seven species-typical calls and not a language. The anatomy of the acoustic system demonstrates that while it is specialised, this is to a similar degree as specialised sensory systems in other mammals with standard brain sizes and therefore cannot be a contributing factor to increased relative brain size. Finally, it is shown that apparent convergences in primate and cetacean behaviour and the behavioural assumptions upon which these are based are unreliable. (8) The observations made are drawn together to demonstrate that water temperature as a selection pressure may explain all facets of the evolution of the modern cetacean brain. The archaeocete/Oligocene cetacean transition, which coincided with major changes in brain mass and scaling, is coincident with a significant reduction in oceanic temperatures. The microanatomy of the cetacean brain, and their altered sleep phenomenology, indicates that the cetacean brain may be an effective thermogenetic organ. The scaling of brain to body mass in cetaceans (or the EQ as based on a mammalian regression) is found to be significantly linked to the range of oceanic temperatures inhabited by the various extant cetacean species." Does somebody want to go find a piece of work that strongly supports the idea that dolphins are really all that smart? Like **pravnik,** I’ve had my doubts. I had this one dolphin neighbor that bought a $30 Best Buy 13 month extended warranty on a $50 radio. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [August 22, 2006, 4:23am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/23 "2006-08-22T04:23:25Z")
[QUOTE=Eleusis] Porpoises, what’s the difference? It’s all a bunch of tree hugging hippie crap! [/QUOTE] What is a bunch of tree hugging hippie crap? Care to explain a random broad brush insult in any detail at all? ---
**Author:** ![threemae](https://avatars.discourse-cdn.com/v4/letter/t/5f9b8f/32.png) [@threemae](https://boards.straightdope.com/u/threemae)\ **Post date:** [August 22, 2006, 4:25am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/24 "2006-08-22T04:25:58Z")
Oh, and before a mod smacks me down, it’s a relatively small proportion of a 46 page review article. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [August 22, 2006, 5:03am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/25 "2006-08-22T05:03:33Z")
[QUOTE=What Exit?] What is a bunch of tree hugging hippie crap? Care to explain a random broad brush insult in any detail at all? [/QUOTE] It’s like rainbows: Everyone thinks they’re wonderful and beautiful, until they crawl up your pantleg and bite you on your ass, and you have to say “No! Bad rainbow! That’s a very bad rainbow!” ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [August 22, 2006, 5:29am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/26 "2006-08-22T05:29:43Z")
[QUOTE=Derleth] It’s like rainbows: Everyone thinks they’re wonderful and beautiful, until they crawl up your pantleg and bite you on your ass, and you have to say “No! Bad rainbow! That’s a very bad rainbow!” [/QUOTE] Man, you have some weird Rainbows in Montana, or is Rainbow the name of your pet snake? Too much LDS in the Sixties? I get the feeling that **Eleusis** is someone who thinks anyone that is pro-animal or pro-environment is a “tree hugging hippie” and part of a crazy group like PETA as opposed to maybe a rational if occasionally too enthusiastic group like Greenpeace, or maybe the Sierra Club, Clean Ocean Action or Clearwater. If you do not like one aspect of the environmental movement it is easy to dismiss everyone in it as being crazy, drugged out Tree huggers. **threemae** : I don’t know for sure that Cetaceans are intelligent or which species are intelligent, but the studies that found that some have self-awareness and tool use would seem to indicate that continued study and protection are well warranted. I guess I will break out my broad brush and believe those that dismiss Cetacean intelligence with disdain are the same people that are in favor of dismantling the Clean Water and Air acts as they hurt business too much. Jim ---
**Author:** ![Eleusis](https://avatars.discourse-cdn.com/v4/letter/e/f4b2a3/32.png) [@Eleusis](https://boards.straightdope.com/u/Eleusis)\ **Post date:** [August 22, 2006, 5:32am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/27 "2006-08-22T05:32:14Z")
[QUOTE=What Exit?] Man, you have some weird Rainbows in Montana, or is Rainbow the name of your pet snake? Too much LDS in the Sixties? I get the feeling that **Eleusis** is someone who thinks anyone that is pro-animal or pro-environment is a “tree hugging hippie” and part of a crazy group like PETA as opposed to maybe a rational if occasionally too enthusiastic group like Greenpeace, or maybe the Sierra Club, Clean Ocean Action or Clearwater. If you do not like one aspect of the environmental movement it is easy to dismiss everyone in it as being crazy, drugged out Tree huggers. [/QUOTE] Both mine, and **Derleth** ’s jokes were quoting Cartman from South Park, as was **boytyperanma** ’s set up. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [August 22, 2006, 5:37am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/28 "2006-08-22T05:37:19Z")
[QUOTE=Eleusis] Both mine, and **Derleth** ’s jokes were quoting Cartman from South Park, as was **boytyperanma** ’s set up. [/QUOTE] Sorry, my bad, you were just imitating a fictional character that does indeed believe all environmentalist are just mental. Guess I need to go back and memorize South Park. Jim {I suppose I am a little sensitive to the Tree hugger remarks, its not easy being green} ---
**Author:** ![DanBlather](https://avatars.discourse-cdn.com/v4/letter/d/f4b2a3/32.png) [@DanBlather](https://boards.straightdope.com/u/DanBlather)\ **Post date:** [August 22, 2006, 6:05am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/29 "2006-08-22T06:05:51Z")
[QUOTE=What Exit?] Too much LDS in the Sixties? [/QUOTE] It was a wonderful time: smoking candy cigarettes, drinking lemonade, and marrying multiple wives. ---
**Author:** ![Ficer67](https://avatars.discourse-cdn.com/v4/letter/f/c57346/32.png) [@Ficer67](https://boards.straightdope.com/u/Ficer67)\ **Post date:** [August 22, 2006, 8:17am UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/30 "2006-08-22T08:17:33Z")
Ok so goldfish will not tag underwater mines and dolphins will. How many different senarios can we construct from this fact? Has anyone cited Doulas Adams yet? ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [August 22, 2006, 12:36pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/31 "2006-08-22T12:36:01Z")
[QUOTE=Ficer67] Has anyone cited Doulas Adams yet? [/QUOTE] See post 16. ---
**Author:** ![js\_africanus](https://avatars.discourse-cdn.com/v4/letter/j/87869e/32.png) [@js\_africanus](https://boards.straightdope.com/u/js_africanus)\ **Post date:** [August 22, 2006, 1:01pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/32 "2006-08-22T13:01:57Z")
[QUOTE=What Exit?] I guess I will break out my broad brush and believe those that dismiss Cetacean intelligence with disdain are the same people that are in favor of dismantling the Clean Water and Air acts as they hurt business too much. [/QUOTE] Does our Clean Water & Air acts apply in South Africa? 'Cos that’s where the author is from. Regardless, it’s not up to me to _dismiss_ Cetacean intelligence, but for you to prove it. (And is “cetacean” a proper noun? Is “canid” capitalized?) Frankly, the evidence I’ve seen for dolphin intelligence has always seemed pretty thin. For example, one documentary raved about how dolphins hunted in packs, a sure sign of great intellingence. It didn’t mention that lions and dogs do that as well, and neither seem to be particularly brilliant. The brain is the brain, and similar structures do similar jobs in different species. For example, the hippocampus is responsible for, among other things, transferring short-term memories into long-term memories. Human children are born with undeveloped hippocampi (pl. ?) and therefore cannot create long-term memories for some years. That’s why humans don’t have memories from an early age. Similarly, lesions to the hippocampus can cause, IIRC Korsakoff’s syndrome, in which the sufferer can’t form long-term memories after the lesion has occured. Similarly, glia cells don’t do any thinking, they’re support staff, so to speak. A big brain that has a high proportion of glia cells implies that the brain/body ratio is not a good indicator of intelligence. As quoted above, “the poorly differentiated neuronal morphology, the low number of neurons and cortical areas, the lack of a distinct pre-frontal cortex, the small hippocampal formation,” don’t combine to a picture of high brain power. The cortex is where a lot of thinking is done, especially the pre-frontal cortex, which does planning and stuff like that. And a small hippocampus implies relatively poor memory formation. Yeah, dolphins can be trained to mark landmines, but that’s not such a thrilling feat when one considers what other animals can be trained to do. Sometimes I get the impression that dolfins are thought to be smart, not because they demonstrate high intelligence, but because they’re smarter than goldfish. ---
**Author:** ![What\_Exit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/what_exit/32/10652_2.png) [@What\_Exit](https://boards.straightdope.com/u/What_Exit)\ **Post date:** [August 22, 2006, 1:51pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/33 "2006-08-22T13:51:06Z")
[QUOTE=js\_africanus] Does our Clean Water & Air acts apply in South Africa? 'Cos that’s where the author is from. Regardless, it’s not up to me to _dismiss_ Cetacean intelligence, but for you to prove it. … [/QUOTE] Glad to see I am not the only touchy one. 😉 The disdain comment was not aimed at you or meant for you. You have only raised good, legitimate questions about the intelligence of Dolphins. That is not disdain, that is simply arguing the other side of the debate. I mistook a joke about Tree-huggers as serious as I have run into many people in real life and a few on the dope that do dismiss all green issues as just “hippy tree-hugging”. I cannot prove or disprove Dolphin intelligence. There are enough studies that have convinced me that we should continue to study cetaceans. None that I can point to a go, here is your proof. Would an Orca’s learning to use bait on its own to catch seagulls and then teaching others in his pod at least lead credence to continuing to study Dolphins? Would the self-awareness tests done with mirrors show that some of these animals may be more intelligent than most primates? Do you even advocate not studying cetaceans? You have not said so, so perhaps we both wish to leave the question open, continue to watch the studies and await the results with the difference being that I am leaning heavily towards there being intelligent and you are leaning towards them not being intelligent. Jim {Sorry if you thought I was insulting you, I appreciate honest, thoughtful questions and doubts about dolphin intelligence, I do not appreciate thoughtless dismissals.} ---
**Author:** ![threemae](https://avatars.discourse-cdn.com/v4/letter/t/5f9b8f/32.png) [@threemae](https://boards.straightdope.com/u/threemae)\ **Post date:** [August 22, 2006, 3:37pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/34 "2006-08-22T15:37:42Z")
I don’t know, I hear lots of stories about dolphins doing really smart things, but where are the studies in the open literature about how smart they actually are? Anyway, I’m not saying they don’t deserve protection, but seeing how I wasn’t aware that they were particularly edangered or anything, is it such a bad thing to have a bit of hankerin’ for some dolphin steak? ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [August 22, 2006, 3:50pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/35 "2006-08-22T15:50:38Z")
[QUOTE=saoirse] Those are porpoises. [/QUOTE] No, you two are thinking of Eskimoes. Eskimoes live in igloos. ---
**Author:** ![ralph124c](https://avatars.discourse-cdn.com/v4/letter/r/8797f3/32.png) [@ralph124c](https://boards.straightdope.com/u/ralph124c)\ **Post date:** [August 22, 2006, 3:54pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/36 "2006-08-22T15:54:28Z")
Size of brain correlates to intelligence? i heard once that many 19th century anatomists collected human brains, to try to corellate size with intelligence. Supposedly, the philosopher/mathematician leibnitz had an abnormally small brain. Likewise for Victor hugo. Anyway, why do dolphins save people from sharks? or is this just hearsay as well? ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 22, 2006, 4:54pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/37 "2006-08-22T16:54:25Z")
> [@](#): > > Anyway, why do dolphins save people from sharks? or is this just hearsay as well? I once read a speculation that dolphins are just pushing people in random directions but we only know about the times when they happen to push somebody back to shore. ---
**Author:** ![saoirse](https://avatars.discourse-cdn.com/v4/letter/s/5daacb/32.png) [@saoirse](https://boards.straightdope.com/u/saoirse)\ **Post date:** [August 22, 2006, 5:48pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/38 "2006-08-22T17:48:20Z")
[QUOTE=DanBlather] It was a wonderful time: smoking candy cigarettes, drinking lemonade, and marrying multiple wives. [/QUOTE] So the love wasn’t free, really, but it wasn’t too pricey, either. ---
**Author:** ![Bippy\_the\_Beardless](https://avatars.discourse-cdn.com/v4/letter/b/ac8455/32.png) [@Bippy\_the\_Beardless](https://boards.straightdope.com/u/Bippy_the_Beardless)\ **Post date:** [August 22, 2006, 6:24pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/39 "2006-08-22T18:24:31Z")
[QUOTE=Ludovic] No, you two are thinking of Eskimoes. Eskimoes live in igloos. [/QUOTE] Don’t be silly. The abstract from the paper shows this is much more interesting than Dolphins don’t jump baracades, so are stoopid. Interesting proposal that the large brain is for heat retention purposes, and the vocalisation being controled from the lower brain leads to speculation about how that vocalisation will be completely alien to Human understanding. (maybe they vocalise subconciously, communicating emotional info, without any level of concious control at all?) ---
**Author:** ![Della](https://avatars.discourse-cdn.com/v4/letter/d/c68b51/32.png) [@Della](https://boards.straightdope.com/u/Della)\ **Post date:** [August 22, 2006, 8:35pm UTC](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512/40 "2006-08-22T20:35:24Z")
[QUOTE=js\_africanus] Similarly, glia cells don’t do any thinking, they’re support staff, so to speak. A big brain that has a high proportion of glia cells implies that the brain/body ratio is not a good indicator of intelligence. As quoted above, “the poorly differentiated neuronal morphology, the low number of neurons and cortical areas, the lack of a distinct pre-frontal cortex, the small hippocampal formation,” don’t combine to a picture of high brain power. The cortex is where a lot of thinking is done, especially the pre-frontal cortex, which does planning and stuff like that. And a small hippocampus implies relatively poor memory formation. Yeah, dolphins can be trained to mark landmines, but that’s not such a thrilling feat when one considers what other animals can be trained to do. [/QUOTE] If you will allow me a quick, semi-off topic nitpick, it’s beginning to look like the role of glia cells extends beyond just support staff. There’s evidence that glia cells can actively take in neurotransmitters and then “strategically” release them at a later time. Chances are that the more we learn about glia the more we will find that they play an important role in cognition. So, just because a brain has tons of glia doesn’t mean that the brain is filled with what amounts to insignificant wasted space. For a back on-topic comment, I kinda hope that dolphins are very intelligent. Of course, any intelligence test that we design will be human-centric and may or may not be able to test whatever facets of intelligence are important for dolphins. [Previous page](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512.md?page=1) [Next page](https://boards.straightdope.com/t/latest-theory-dolphins-are-actually-pretty-stupid/369512.md?page=3)