Editing Petroglyph (section)

==Interpretation==
Many hypotheses exist as to the purpose of petroglyphs, depending on their location, age, and subject matter. Some petroglyph images most likely held a deep cultural and religious significance for the societies that created them. Many petroglyphs are thought to represent a type of symbolic or ritualistic language or communication style that remains not fully understood. Others, such as [[geocontourglyph]]s, more clearly depict or represent a landform or the surrounding terrain, such as rivers and other geographic features.{{citation needed|date=May 2022}}

Some petroglyph maps, depicting trails, as well as containing symbols communicating the time and distances travelled along those trails, exist; other petroglyph maps act as astronomical markers. As well as holding geographic and astronomical importance, other petroglyphs may also have been a by-product of various rituals: sites in India, for example, have seen some petroglyphs identified as musical instruments or "[[rock gong]]s".<ref>[http://news.bbc.co.uk/2/hi/science/nature/3520384.stm Ancient Indians made 'rock music']. BBC News (2004-03-19). Retrieved on 2013-02-12.</ref>

Some petroglyphs likely formed types of symbolic communication, such as types of [[proto-writing]].<ref>{{Cite journal|last=Houston|first=Stephen D.|date=2004-10-01|title=The Archaeology of Communication Technologies|url=https://www.annualreviews.org/doi/10.1146/annurev.anthro.33.070203.143724|journal=Annual Review of Anthropology|volume=33|issue=1|pages=223–250|doi=10.1146/annurev.anthro.33.070203.143724|issn=0084-6570|url-access=subscription}}</ref> Later glyphs from the [[Nordic Bronze Age]] in Scandinavia seem to refer to some form of territorial boundary between [[tribe]]s, in addition to holding possible religious meanings. Petroglyph styles have been recognised as having local or regional "dialects" from similar or neighboring peoples. [[Siberian inscriptions]] loosely resemble an early form of [[Runic alphabet|runes]], although no direct relationship has been established.

Petroglyphs from different continents show similarities. While people would be inspired by their direct surroundings, it is harder to explain the common styles. This could be mere coincidence, an indication that certain groups of people [[Human migration|migrated]] widely from some initial common area, or indication of a common origin. In 1853, [[George Tate (topographer)|George Tate]] presented a paper to the Berwick Naturalists' Club, at which a [[John Collingwood Bruce]] agreed that the carvings had "... a common origin, and indicate a symbolic meaning, representing some popular thought."<ref>J. Collingwood Bruce (1868; cited in Beckensall, S., ''Northumberland's Prehistoric Rock Carvings: A Mystery Explained''. Pendulum Publications, Rothbury, Northumberland. 1983:19)</ref> In his cataloguing of Scottish rock art, Ronald Morris summarized 104 different theories on their interpretation.<ref>Morris, Ronald (1979) ''The Prehistoric Rock Art of Galloway and The Isle of Man'', Blandford Press, {{ISBN|978-0-7137-0974-2}}.</ref>

Other theories suggest that petroglyphs were carved by spiritual leaders, such as [[shaman]]s, in an [[altered state of consciousness]],<ref>[See: D. Lewis-Williams, ''A Cosmos in Stone: Interpreting Religion and Society through Rock Art'' (Walnut Creek, CA: Altamira Press, 2002).]</ref> perhaps induced by the use of natural [[Psychedelics, dissociatives and deliriants#Hallucinogenic plants, fungi, and animals|hallucinogens]]. Many of the [[Geometry|geometric]] [[pattern]]s (known as [[form constant]]s) which recur in petroglyphs and [[cave paintings]] have been shown by David Lewis-Williams to be hardwired into the human brain. They frequently occur in visual disturbances and hallucinations brought on by drugs, [[migraine]], and other stimuli.

The Rock Art Research Institute (RARI) of the [[University of the Witwatersrand]] studies present-day links between religion and rock art among the [[San people]] of the [[Kalahari Desert]].<ref>[http://rockart.wits.ac.za/ Rockart.wits.ac.za] {{Webarchive|url=https://web.archive.org/web/20170730134938/http://rockart.wits.ac.za/ |date=2017-07-30 }} Retrieved on 2013-02-12.</ref> Though the San people's artworks are predominantly paintings, the beliefs behind them can perhaps be used as a basis for understanding other types of rock art, including petroglyphs. To quote from the RARI website:
<blockquote>Using knowledge of San beliefs, researchers have shown that the art played a fundamental part in the religious lives of its painters. The art captured things from the San's world behind the rock-face: the other world inhabited by spirit creatures, to which dancers could travel in animal form, and where people of ecstasy could draw power and bring it back for healing, rain-making and capturing the game.<ref>{{cite web|title=Rock Art Research Institute (RARI)|url=https://www.wits.ac.za/rockart/|website=University of the Witwatersrand, Johannesburg.|access-date=9 September 2017}}</ref></blockquote>