Editing Dolphin (section)

==Intelligence==
{{further|Cetacean intelligence|Cetacean surfacing behaviour}}
[[File:Dolphin Encounter-9563.jpg|thumb|The face of a [[common bottlenose dolphin]]]]
Dolphins are known to teach, learn, cooperate, scheme, and grieve.<ref name=wwwu>{{cite news |last=Siebert |first=Charles |title=Watching Whales Watching Us |work=The New York Times Magazine |date=July 8, 2009|access-date=August 29, 2015 |url=https://www.nytimes.com/2009/07/12/magazine/12whales-t.html?pagewanted=all}}</ref> The neocortex of many species is home to elongated [[spindle neurons]] that, prior to 2007, were known only in hominids.<ref>{{cite journal |author=Watson, K.K. |title=Dendritic architecture of the Von Economo neurons |journal=Neuroscience |volume=141 |issue=3 |pages=1107–1112 |year=2006 |doi=10.1016/j.neuroscience.2006.04.084 |last2=Jones |first2=T. K. |last3=Allman |first3=J. M. |pmid=16797136|s2cid=7745280 }}<!--|access-date=August 29, 2015--></ref> In humans, these cells are involved in social conduct, emotions, judgment, and theory of mind.<ref>{{cite journal |author=Allman, John M. |title=Intuition and autism: a possible role for Von Economo neurons |journal=Trends Cogn Sci |volume=9 |issue=8 |pages=367–373 |year=2005 |doi=10.1016/j.tics.2005.06.008 |last2=Watson |first2=Karli K. |last3=Tetreault |first3=Nicole A. |last4=Hakeem |first4=Atiya Y. |pmid=16002323|s2cid=14850316 }}</ref> Cetacean spindle neurons are found in areas of the brain that are analogous to where they are found in humans, suggesting that they perform a similar function.<ref>{{cite journal |author=Hof, Patrick R. |title=Structure of the cerebral cortex of the humpback whale, ''Megaptera novaeangliae'' (Cetacea, Mysticeti, Balaenopteridae) |journal=The Anatomical Record |volume=290 |issue=1 |pages=1–31 |year=2007 |doi=10.1002/ar.20407 |last2=Van Der Gucht |first2=Estel |s2cid=15460266 |pmid=17441195|doi-access=free }}<!--|access-date=August 29, 2015--></ref>

[[Brain size]] was previously considered a major indicator of the intelligence of an animal. Since most of the brain is used for maintaining bodily functions, greater ratios of brain to body mass may increase the amount of brain mass available for more complex cognitive tasks. [[Allometric]] analysis indicates that mammalian brain size scales at approximately the two-thirds or three-fourths exponent of the body mass. {{Clarify|date=June 2022}}<ref>{{cite web |url=http://pages.ucsd.edu/~jmoore/courses/allometry/allometry.html |title=Allometry |first=Jim |last=Moore| publisher=University of California San Diego |access-date=August 9, 2015}}</ref> Comparison of a particular animal's brain size with the expected brain size based on such allometric analysis provides an [[encephalization quotient]] that can be used as another indication of animal intelligence. [[Orca]]s have the second largest brain mass of any animal on earth, next to the [[sperm whale]].<ref>{{cite journal|url=http://articles.orlandosentinel.com/2010-03-06/news/os-seaworld-killer-whale-brains-20100302_1_killer-whales-orcas-dolphin-or-porpoise|archive-url=https://archive.today/20120703134702/http://articles.orlandosentinel.com/2010-03-06/news/os-seaworld-killer-whale-brains-20100302_1_killer-whales-orcas-dolphin-or-porpoise|url-status=dead|archive-date=July 3, 2012|title=How smart are they?|journal=Orlando Sentinel|date=March 7, 2010}}</ref> The [[brain to body mass ratio]] in some is second only to humans.<ref>{{cite web |url=http://blogs.scientificamerican.com/news-blog/are-whales-smarter-than-we-are/ |author=Fields, R. Douglas |title=Are whales smarter than we are? | work=Scientific American |access-date=August 9, 2015}}</ref>

[[Self-awareness]] is seen, by some, to be a sign of highly developed, abstract thinking. Self-awareness, though not well-defined scientifically, is believed to be the precursor to more advanced processes like [[metacognition|meta-cognitive reasoning]] (thinking about thinking) that are typical of humans. Research in this field has suggested that cetaceans, among others, possess self-awareness.<ref>{{cite web | url=http://www.livescience.com/4272-elephant-awareness-mirrors-humans.html | title=Elephant Self-Awareness Mirrors Humans |publisher=Live Science |date=October 30, 2006 |access-date=August 29, 2015}}</ref>
The most widely used test for self-awareness in animals is the [[mirror test]] in which a mirror is introduced to an animal, and the animal is then marked with a temporary dye. If the animal then goes to the mirror in order to view the mark, it has exhibited strong evidence of self-awareness.<ref name="Mirror test">{{cite news |url=https://www.nytimes.com/2001/05/01/science/brainy-dolphins-pass-the-human-mirror-test.html |title=Mirror test |author=Derr, Mark |work=The New York Times|date=May 2001 |access-date=August 3, 2015}}</ref>

Some disagree with these findings, arguing that the results of these tests are open to human interpretation and susceptible to the [[Clever Hans]] effect. This test is much less definitive than when used for primates, because primates can touch the mark or the mirror, while cetaceans cannot, making their alleged self-recognition behavior less certain. Skeptics argue that behaviors that are said to identify self-awareness resemble existing social behaviors, and so researchers could be misinterpreting self-awareness for social responses to another individual. The researchers counter-argue that the behaviors shown are evidence of self-awareness, as they are very different from normal responses to another individual. Whereas apes can merely touch the mark on themselves with their fingers, cetaceans show less definitive behavior of self-awareness; they can only twist and turn themselves to observe the mark.<ref name="Mirror test"/>

In 1995, Marten and Psarakos used television to test dolphin self-awareness.<ref>{{cite journal|last1=Marten|first1=Ken|last2=Psarakos|first2=Suchi|title=Using Self-View Television to Distinguish between Self-Examination and Social Behavior in the Bottlenose Dolphin (Tursiops truncatus)|journal=Consciousness and Cognition|volume=4|number=2|date=June 1995|doi=10.1006/ccog.1995.1026|pages=205–224|pmid=8521259|s2cid=44372881}}</ref> They showed dolphins real-time video of themselves, video of another dolphin and recorded footage. They concluded that their evidence suggested self-awareness rather than social behavior. While this particular study has not been repeated since then, dolphins have since passed the mirror test.<ref name="Mirror test"/> Some researchers have argued that evidence for self-awareness has not been convincingly demonstrated.<ref>Gallup Jr, Gordon G., and James R. Anderson. "Self-recognition in animals: Where do we stand 50 years later? Lessons from cleaner wrasse and other species." Psychology of Consciousness: Theory, Research, and Practice (2019).</ref>