Cognition in nonhuman animals




Mirror test

Scent test


Contagious yawning

Contagious yawning has been experimentally demonstrated in humans, dogs, chimpanzees, and baboons.


Object permanence



Notable individuals: Azy, Fu Manchu, Kanzy, Koko, Ndume, Nim Chimpsky, Nyota, Sandra, Washoe


Horses have been experimentally demonstrated to be able to anticipate their comfort in the future and use symbol boards to communicate their preferences accordingly.[2]


Dogs are capable of recognizing their own scent in unfamiliar situations and will spend substantially less time investigating it, a difference that develops with age,[3] which has been cited as evidence of a capacity for self-recognition. They also experience contagious yawning with other dogs and humans, with a bias towards familiar humans, indicating some empathic capacity.[4]


Notable individuals: Hoover




Notable individuals: Melanie


Elephants have observed mourning their own deceased,[6] as well as humans.[7]

When Asian elephants (Elephas maximus) were tested, one individual (a female named Happy) investigated a mark made on her head using the mirror, and did not investigate a similar mark made with colorless paint.[8]

Notable individuals: Batyr, Happy


Alex the grey parrot and zero

At least one individual, [Alex], was observed practicing words when alone.[9]

Magpie grieving rituals

New Caledonian crows (Corvus moneduloides) demonstrate simple tool use, and even modifying flexible material (such as leaves and wire) into hooks.[10] Common ravens (Corvus corax) have been observed anticipating observation by unseen competitors when caching food,[11] which has been argued to be evidence of a theory of mind.[12]

Eurasian magpies (Pica pica) pass the mirror self-recognition test.

Monk Parakeets surviving in Chicago despite climate

Notable individuals: Alex, Cosmo, N'kisi, Sparkie Williams



Cleaner Wrasses were the first fish to pass the mirror test. They also appear to have some degree of , and have the unusual distinction of improving other species' cognitive abilities through their parasite removal behavior.[13]


The Giant oceanic manta ray (Manta birostris) did not engage in social behaviors when presented with a mirror, instead engaging in unusual and repetitive movements that may be self-examination.[14] Rays have exceptionally large and well-developed brains for their size, supporting an intelligence reflected across many behavior tests.[15]


Daffodil chichlids (Neolamprologus pulcher), when subjected to mirror testing, acclimated to their mirror images but did not appear to investigate marks on themselves.[16]



Bees are capable of observational learning[17], and can count and recognize quantities up to four.[18] They are also able to grasp zero as a quantity and order it lower than one in a counting sequence.[19]

External Links


  1. Can animals think? by Eugene Linden, Time, 1999-08-29
  2. Cecilie M. Mejdell, Turid Buvik, Grete H.M. Jørgensen, Knut E. Bøe. (November 2016). "Horses can learn to use symbols to communicate their preferences". Applied Animal Behaviour Science. 184: 66-73. doi:[1]
  3. Cazzolla Gatti, Roberto. (November 2015). "Self-consciousness: beyond the looking-glass and what dogs found there". Ethology Ecology & Evolution. 28: 232-240. doi:[2]
  4. Romero T, Konno A, Hasegawa T. (August 2013). "Familiarity Bias and Physiological Responses in Contagious Yawning by Dogs Support Link to Empathy". PLOS ONE 8(8): e71365. doi:[3]
  5. Pettit, Michael: Raccoon intelligence at the borderlands of science, American Psychological Association Monitor on Psychology, November 2010.
  6. Grief in animals: It's arrogant to think we're the only animals who mourn by Marc Bekoff Ph.D., Psychology Today, October 29, 2009
  7. Elephants Mourn Loss of "Elephant Whisperer" Lawrence Anthony by Marc Bekoff Ph.D., Psychology Today, March 07, 2012
  8. (). "". . . doi:[]
  9. Wise, Steven M. (2002). Drawing the Line. Cambridge, Massachusetts: Perseus Books. p. 93. ISBN 0-7382-0340-8.
  10. Alex A. S. Weir, Jackie Chappell, Alex Kacelnik. (August 2002). "Shaping of Hooks in New Caledonian Crows". Science. 297(5583): 981. doi:[4] PDF mirror
  11. Thomas Bugnyar, Stephan A. Reber & Cameron Buckner. (February 2016). "Ravens attribute visual access to unseen competitors". Nature Communications. doi:[5]
  12. Ravens' fear of unseen snoopers hints they have theory of mind, Sam Wong, New Scientist, 2016-02-02
  13. The Fish That Makes Other Fish Smarter by Ed Yong, The Atlantic, March 07, 2018
  14. Ari, Csilla & D'Agostino, Dominic. (March 2016). "Contingency checking and self-directed behaviors in giant manta rays: Do elasmobranchs have self-awareness?". Journal of Ethology. 34. doi:[6]
  15. Manta ray brainpower blows other fish out of the water by Amy McDermott, Oceana, 2017-07-25
  16. Takashi Hotta, Shiho Komiyama, Masanori Kohda. (January 2018). "A social cichlid fish failed to pass the mark test". Animal Cognition. 21(1):127-136. doi:[7]
  17. Olli J. Loukola, Clint J. Perry, Louie Coscos, Lars Chittka. (February 2017). "Bumblebees show cognitive flexibility by improving on an observed complex behavior". Science. 355(6327):833-836. doi:[8]
  18. Peter Skorupski , HaDi MaBouDi , Hiruni Samadi Galpayage Dona , and Lars Chittka. (January 2018). "Counting insects". Philosophical Transactions of The Royal Society B: Biological Sciences. 373(1740). doi:[9]
  19. Scarlett R. Howard, Aurore Avarguès-Weber2, Jair E. Garcia1, Andrew D. Greentree, Adrian G. Dyer. (June 2018). "Numerical ordering of zero in honey bees". Science. 360(6393): 1124-1126. doi:[10]