2018 Update on Earth’s Smartest Animal Genera

The_Forum_smallAs time goes by we become ever better acquainted with the abilities of the other animals with which we share the Earth. For many of the smartest, we already have enough data to place them with greater reliability than usually acknowledged. This is especially true of terrestrial forms. For 46 of them in my top 80, intelligence can be estimated directly and via multiple types of cognitive performance. By these, I place a figure in brackets. This figure is based on our familiar IQ scale, though its baseline is much lower and doesn’t shift from decade to decade as the human scale does.  I re-calibrated my scale with better data, a wider primate database, and an original one for cetaceans. The cognitive gap between chimpanzees, and gorillas is wider than I originally calculated, and intelligence looks as if it rises more steeply with neocortical neuron number than I originally measured. As a consequence, my original calculations for most animals below the chimp cognitive class were too high by about 50 points. Since almost all earlier calculations made on this site, were referenced to neuron number, not brain size, I reset my scale, at the beginning of 2017, to preserve the originally calculated slope of intelligence vs neuron number. As such, I have redefined it as follows… The intelligence of x IQ points corresponds to the expected intelligence of a primate species with either

  1. A brain mass of y: x = 50* ln(y/20g)
  2. A neocortical neuron count of w: x = 65*ln(w) – 1300
  3. A cognitive z score among all primate genera: x = 75z + 20

The data I currently possess finds all three of these definitions to be equivalent, though the last is always preferred.

For cetaceans, other than the bottlenose dolphin (where  comparative performance data is available against many primates), a completely different scale is used whereby x IQ points corresponds to the expected intelligence of a cetacean species with either

  1. A brain mass of y: x = 50ln(y/60g)
  2. A neocortical neuron count of w: x = 65ln(w)  – 1340
  3. A cognitive z score among all cetacean species: x = 50z + 140

The figures for this cetacean-only scale have been placed in square brackets.

If I have set the slope of these scales correctly then, as with our familiar IQ scale, differences greater than 25 points will imply that there will exists many tasks that the higher ranked animal can intuit, yet the lower ranked one can never be made to solve, irrespective of how long the training or hard the effort. As a corollary, differences of this order (>25 points) should allow us to tell which animal genus is the more intelligent, no matter how different the nature of their intelligence is, given only that we have done many different types of tests on them. By contrast, I expect the placings of those animals for which no figure is given to change greatly as more data becomes available.

Here is the list of the most intelligent animals by genus as I see them as of January 2018.

Earth’s 80 Most Gifted Animals by Genus

1 [300] Sperm whale

2 (300 includingFlynn effect) Human

Both of the above animals are united by many unique factors not seen in any others, including

  • Specific activity has a dominant effect on the fertility of its domain (= probable farming)
  • Social group more important in predicting survival than genetics or location (= true culture)
  • Vocalisations partition among social groups in a way that sharply defines thousands of tribes/pods as belonging to one custom, in a way that can’t be explained by genetics, geographic environment nor by vocal learning by those around you (= true language)

3 [270] Humpback whale

4 [225] Killer whale

5 [215] Fin whale

6 [210] Pilot whale

above this line, all should share these common features

  • All adults expected to pass the mirror self-recognition test (MSR)
  • Much higher forebrain neuron count than other animals, >10 billion

 

7 (200) Chimpanzee

African elephant

9 (185) Orangutan

10 [190] False Killer Whale

11 [180] Beluga whale

12 (175)[215] Bottlenose dolphin read HERE

13 [170] Bowhead whale

14 [170] Risso’s dolphin

15 [170] Cuvier’s beaked whale

16 (160) Asian elephant

17 [160] Striped dolphin

18 [155] Gray whale

19 (150) Gorilla

20 [150] Common dolphin

21 [150] Gervais beaked whale

22 [140] Pygmy sperm whale

23 [140] Chinese white dolphin

24 Bottlenose whale

25 Walrus

26 [140] Right whale

27 (135) California sea lion

28 Melon-headed whale

above this line, all should share these common features

  • expected to use tools when available
  • some adults should show MSR
  • brains contain spindle cells
  • > 4 billion forebrain neurons

 

29 [125] Harbour porpoise

30 Pygmy killer whale

31 [125] Narwhal

32 [105] Fraser’s dolphin

33 [105] Rough-toothed dolphin

34 [105] Atlantic white-sided dolphin

35 Elephant seal

36 (105) Macaque

37 [105] Dall’s porpoise

38 (100) Siamang

39 Polar bear (carnivore)

40 (100)  Kea (parrot) see HERE

41 (100) New Caledonian crow see HERE

42 Northern right whale dolphin

43 [90] Heaviside’s dolphin

44 Mimic octopus

45 (90) Sea otter

46 (90) Robust Capuchin

47 (90) Spider monkey

48 (90) Grey langur

49 Nomascus genus of gibbons

50 Snub-nosed monkey

51 (85) African grey parrot  – read HERE

52 (85) Baboon

53 Hoolock  gibbon

54 Hyacinth macaw

55 Stellar sea lion

56 Leopard seal

57 Goffin’s (>Sulphur crested) cockatoo

58 Veined octopus

above this line, all should share these common features

  • occasional tool use if situation allows it
  • close to 100% of adults pass the cylinder test of ‘self-control’
  • show clear signs of metacognition
  • > 1.5 billion forebrain neurons (vertebrates)

59 Crested mangabey

60 Douc

61 Proboscis monkey

62 [80] Baiji

63 Blue and gold / scarlet macaw

64 [75] Amazon river dolphin

65 hippopotamus

66 (70) Guenon

67 South American sea lion

68 Crabeater seal

69 Weddell seal

70 Southern fir seal

71 Amazon parrot

72 Eurasian magpie

73 (65) Patas monkey

74 (65) Gelada (primate)

75 Finless porpoise

76 Common octopus

77 Palm cockatoo (parrot)

78 Manta ray

79 Red colobus

80 Green Monkey

 

Colour Key

BLUE cetaceans

BLACK primates

GREEN carnivores

ORANGE parrots

RED songbirds

VIOLET octopuses

BROWN proboscideans

ROYAL BLUE even-toed ungulates

AQUA batoids

Most Intelligent Animal Groups

Primates

Best studied of all are the primates. So much more is known of the primates, that they provide the framework around which I have attempted to fit animals from all other groups. They are traditionally seen as the most cognitively advanced order, so it might be reasonable to suppose that their 72 genera would dominate this list, but recent evidence indicates that they have many challengers.

crow

Birds

Songbirds and parrots are now thought of as two of the most intelligent groups. Unlike primates, however, a very high ability at one particular tasks does not strongly suggest high cognitive abilities in others. There is even evidence that some talents correlate negatively with other abilities in this group, a phenomenon never detected in any mammalian group. An example of this modularity is that the Eurasian magpie is the only bird to have passed the mirror test, yet most specialists think it less intelligent than the crow. This makes comparisons of birds with other animals on any one task misleading, and has given rise to some ridiculous claims such as equating the perception by some birds that stones into water might alter its level with that of human children, who only tend to glean that possibility between ages 5-7.

Despite the aforementioned difficulties, a few birds, such as crows and kea, have been studied on so many tasks that we can begin to make true comparisons. Their general abilities can be placed at, at least, the level of the gracile genus of Capuchins, with some special abilities reaching as high as the great apes. Another clue as to where to place them comes from a recent study of the number of neurons in their pallium. If a primate species had the same number of neurons in its forebrain as either bird (1.2 billion), its expected intelligence on the below scale would be 60.  We should also account for the crow not being a bird picked at random, but one that has tested very highly, so 60 would be expected to underrate their intelligence. Also to be noted, is that New Caledonian crows prove significantly better problem solvers than common crows.

800px-Bottlenose_dolphin_with_young

Cetaceans

For the cetaceans, bottlenose dolphins are in a similar position to the most intelligent tested birds. Though their tool use is low, they show other areas where they exceed all well studied primates, excluding the great apes. There are fifteen cetacean genera with species of larger brains size than these dolphins. So much less data is available with which we can assess their intelligence than for bottlenose dolphins, that it would be no surprise if many more than give above fitted into this human to chimpanzee/orangutan gap in the primate cognitive table.

Batoids

Fish have proved more intelligent than previously recognised. Once more, this group provides evidence that absolute brain size is far more important than relative brain size. It is among the large batoid rays that we see the most obvious signs of intelligence. By contrast, the osteoglossiformes, some of which which are distinguished by the highest proportional energy demands by their brains (and the only group known to spend a higher proportion of their energy budget on their brain than humans), have not shown any signs of higher intelligence. Of the batoids, it is its largest member that is repeatedly mentioned as showing signs of very high intelligence. This possibility is bolstered by laboratory studies, in which manta rays are the only fish known to show signs of passing the mirror test of self recognition. Confusingly, many websites wrongly state that manta rays have the highest relative brain size or encephalisation quotient among fish. The truth is they fail that by a long chalk, but do belong to a group that collectively has one of the higher EQs among fish. It should be no surprise then, to find that the manta ray has the largest absolute brain size of any fish, at 270g.

Carnivores

So many mammalian carnivores belong to a single order, that this group is refereed to as simply ‘carnivores’. Many cats, dogs, bears and seals have scored well on cognitively loaded tests. Seals may be the most underrepresented carnivores on our list. On the other hand, seals held in captivity are allowed the luxury of persist unihemispheric sleep, such that current testing may overrate the abilities of those in the wild. Otters may also turn out to be underrepresented, though it is my pick that the sea otter (45th on my list) will turn out to be far more intelligent than otters of other genera.

Octopus_vulgaris_Merculiano

Octopuses

Octopuses are our sixth group with many candidate genera for the gifted list. One such genus has over a hundred species, which makes finding its smartest species a challenge in itself. Because so much of their intelligence resides in their arms (really!), their intellect is notoriously hard to assess. If they miss the top 50, their most intelligent will not be far behind. Amphioctopus and Enteroctopus have shown they can combine foresight with tool use, and Octopus may have shown that it can learn by observing even though it is not a social animal. Thaumoctopus shows such body and skin colour control combined with fast information processing, that it can mimic other animals closely. Such a display of specialised intelligence (Thaumoctopus)  is so far above anything similar in the rest of the animal kingdom, as to hint at a very high general intelligence.

Selected Near Misses

Lutung

La Plata dolphin

Caribbean monk seal

Bearded seal

Hooded seal

Swamp monkey

(50) Surili (primate)

Western scrub jay (corvid)

(50) Mandrill (primate)

(50) Woolly monkey

(45) Gracile Capuchin (primate)

(45) Mangabey (primate)

Woodpecker finch

Tuxuci

(40) Dwarf gibbon (primate)

(40) Horse (odd-toed ungulate)

South Asian river dolphin

(35) Raccoon

Monk parakeet (parrot)

(35) Wolf (carnivore)

Giant Pacific octopus

(25) Howler monkey

Spotted hyena

(25) Tamarin (primate)

(20) Black and white colobus

(15) Titi

above this line, all should share these common features

  • Some adults pass the cylinder test
  • Show some understanding of abstract concepts
  • marginal signs of metacognition

(10) Pig (even-toed ungulate)

Pinyon jay (corvid)

(5) Aye-aye

(0) Ruffed lemur (primate)

(-10) greater galago

(-20) squirrel monkey

 

Summary: Some genera are included in the top 80 list on tenuous grounds. Others are more robustly placed. Almost all primates and cetaceans were placed according to objective data only. For the primates,  most of that was direct cognitive testing and behavioural observation. My expectation is that a perfect list of the 100 cleverest animals would contain at least 50 of those 80, and all those with bracketed numbers >70.

My current list of 80 contains 31 cetaceans, 22 primates, 7 parrots, 11 carnivores, two passerines, both proboscideans, and three octopuses. This mix is distorted by there being far more cognitive data on primates than any other order. Also notable, is the limited scope of cognitive studies of large carnivores, particularly pinnipeds. Some other large brained animals have also been particularly poorly studied, notably the giraffe and the camel, Although neither of these two is likely to rival the chimpanzee, both have slightly larger brains, and I would not be surprised if both bettered the Capuchin, despite neither making the current list due to the paucity of data.