Editing Addition (section)

=== Innate ability ===
Studies on mathematical development starting around the 1980s have exploited the phenomenon of [[habituation]]: [[infant]]s look longer at situations that are unexpected.{{sfnp|Wynn|1998|p=5}} A seminal experiment by [[Karen Wynn]] in 1992 involving [[Mickey Mouse]] dolls manipulated behind a screen demonstrated that five-month-old infants ''expect'' {{nowrap|1 + 1}} to be 2, and they are comparatively surprised when a physical situation seems to imply that {{nowrap|1 + 1}} is either 1 or 3. This finding has since been affirmed by a variety of laboratories using different methodologies.{{sfnp|Wynn|1998|p=15}} Another 1992 experiment with older [[toddler]]s, between 18 and 35&nbsp;months, exploited their development of motor control by allowing them to retrieve [[ping-pong]] balls from a box; the youngest responded well for small numbers, while older subjects were able to compute sums up to 5.{{sfnp|Wynn|1998|p=17}}

Even some nonhuman animals show a limited ability to add, particularly [[primate]]s. In a 1995 experiment imitating Wynn's 1992 result (but using [[eggplant]]s instead of dolls), [[rhesus macaque]] and [[cottontop tamarin]] monkeys performed similarly to human infants. More dramatically, after being taught the meanings of the [[Arabic numerals]] 0 through 4, one [[Common Chimpanzee|chimpanzee]] was able to compute the sum of two numerals without further training.{{sfnp|Wynn|1998|p=19}} More recently, [[Asian elephant]]s have demonstrated an ability to perform basic arithmetic.<ref>{{cite news |newspaper=The Guardian |last=Randerson |first=James |url=https://www.theguardian.com/science/2008/aug/21/elephants.arithmetic |title=Elephants have a head for figures |date=21 August 2008 |access-date=29 March 2015 |archive-url=https://web.archive.org/web/20150402103526/http://www.theguardian.com/science/2008/aug/21/elephants.arithmetic |archive-date=2 April 2015 |url-status=live }}</ref>