Editing Encephalization quotient (section)

{{Short description|Relative brain size measure}}
{{distinguish|cephalic index}}
{{cleanup|reason=multiple unresolved issues as per talk page|date=April 2016}}
{{Use dmy dates|date=November 2019}}
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|colspan="2" style="text-align: left;" |EQ relative to the cat as standard species: EQ(cat)=1 -->
'''Encephalization quotient''' ('''EQ'''), '''encephalization level''' ('''EL'''), or just '''encephalization''' is a relative [[brain size]] measure that is defined as the ratio between observed and predicted brain mass for an animal of a given size, based on [[nonlinear regression]] on a range of reference species.<ref>{{cite book|last1=Pontarotti|first1=Pierre|title=Evolutionary Biology: Convergent Evolution, Evolution of Complex Traits|date=2016|publisher=Springer|isbn=978-3-319-41324-2|pages=74}}</ref><ref>{{cite web |title=Natural Sciences 102: Lecture Notes: Emergence of Intelligence |author=G.Rieke |url=http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/intelligence.htm |access-date=12 February 2011 |archive-date=7 April 2019 |archive-url=https://web.archive.org/web/20190407181204/http://ircamera.as.arizona.edu/NatSci102/NatSci102/lectures/intelligence.htm |url-status=dead }}</ref> It has been used as a proxy for [[intelligence]] and thus as a possible way of comparing the intelligence levels of different [[species]]. For this purpose, it is a more refined measurement than the raw [[brain-to-body mass ratio]], as it takes into account [[allometric]] effects. Expressed as a formula, the relationship has been developed for [[mammals]] and may not yield relevant results when applied outside this group.<ref name=Moore>{{cite web |author=Moore, J. |year=1999 |url=http://weber.ucsd.edu/~jmoore/courses/allometry/allometry.html |title=Allometry |publisher=[[University of California]], San Diego |access-date=5 January 2011 |archive-date=27 March 2019 |archive-url=https://web.archive.org/web/20190327101353/http://pages.ucsd.edu/~jmoore/courses/allometry/allometry.html |url-status=dead }}</ref>