View source for Cleavage

'''Cleavage''' is the cleft created by the partial exposure of a woman's [[breasts]], especially when exposed by low-cut clothing. The neckline of a garment that exposes cleavage is known as ''décolletage'' (or ''décolleté'' in current French). ''Intermammary sulcus'' or ''intermammary cleft'' are the terms adopted by the International Federation of Associations of Anatomists for the area of cleavage between the breasts not including the breasts. Exposure of the underside of the breast, such as below an extremely short crop top, is known as ''neathage''<ref>[http://www.urbandictionary.com/define.php?term=neathage Urban Dictionary: Neathage]</ref>, ''reverse cleavage''<ref>[http://www.urbandictionary.com/define.php?term=reverse+cleavage Urban Dictionary: Reverse cleavage]</ref> or ''underboob''<ref>[http://www.urbandictionary.com/define.php?term=underboob Urban Dictionary: Underboob]</ref>, or ''Australian cleavage''<ref>[http://www.urbandictionary.com/define.php?term=Australian+cleavage Urban Dictionary: Australian cleavage]</ref> (because the down under side of the breast is exposed). When the lateral aspects of the breasts are uncovered, it is known as ''side cleavage'' or ''sideboob''.

== Theories of cleavage ==
Some evolutionary psychologists theorize that humans' permanently enlarged breasts, in contrast to other primates' breasts that only enlarge during ovulation, allowed females to "solicit male attention and investment even when they are not really fertile."<ref>Charles B. Crawford & Dennis Krebs (eds.), [http://books.google.com/books?id=B96QZyBluRgC&pg=PA113&lpg=PA113&dq=%22flat+chested+ape+to+modern+buxom+woman%22&source=web&ots=RaQ7YIBwJ2&sig=cDIuiyc56Xi7rd8ZbXsU9wuraL4#PPA113,M1 "How Mate Choice Shaped Human Nature"], ''Handbook of Evolutionary Psychology: Ideas, Issues, and Applications'', Lawrence Erlbaum Associates (1998).</ref>  Popular [[British]] zoologist and ethologist Desmond Morris theorizes that cleavage is a sexual signal that imitates the image of the cleft between the buttocks<ref name="theory">http://sil.mcmaster.ca/Archive/life/041014lifefeature.html</ref>, which according to ''The Naked Ape'' is also unique to humans, other apes as a rule having much flatter buttocks.  However it is worth noting that, as far as is known, humans have never had breasts that would have much cleavage even when they are unclothed, so breast cleavage is a phenomenon of modern, clothed humans.

== Cleavage variant illustrations==
[[Image:Haley Crush Australian cleavage.jpg|left|thumb|999x190px|[[Haley Crush]]’s Australian cleavage]]
[[Image:Tiffany_taylor_neathage.jpg|left|thumb|999x190px|[[Tiffany Taylor]]’s Australian cleavage [[:Category:Hair-bra images|hair bra]]]]
[[Image:Lucy_pinder_sideboob.jpg|left|thumb|999x190px|[[Lucy Pinder]]’s sideboob cleavage]]
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== See also ==
* {{cl|Cleavage images}}
* {{cl|Underboob images}}

== External links ==
* [http://www.humanitiesweb.org/human.php?s=g&p=a&a=i&ID=424 "Sargent's Portraits"], an article including a mention of the scandal caused by the portrayal of cleavage in John Singer Sargent's "Portrait of Madame X". 
* [http://www.azcentral.com/style/articles/0314bosom.html "Cleavage Is Back by Cheryl Lu-Lien Tan, The Baltimore Sun"], viewed 9 June 2007.

== References ==
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{{GFDL|Cleavage (breasts)}}

[[Category:Research]]