Editing Great ape language (section)

==1930s: Cross-fostering and efforts to teach speaking==

The next line of research came out of [[cross-fostering]] studies, where chimpanzees were raised in human homes as children. Primatologist [[Robert Yerkes]] launched one such project. He recruited Luella and [[Winthrop Niles Kellogg]], scientists at [[Indiana University]], to raise a chimp named [[Gua (chimpanzee)|Gua]] alongside their human child, Donald.<ref>{{Cite book |last=Halloran |first=Andrew |title=The Song of the Ape: Understanding the Languages of Chimpanzees |date=March 2012 |publisher=St. Martin's Press |edition=First |location=New York |pages=18}}</ref> In ''The Ape and the Child'', the Kelloggs wrote that "it was very clear during the first few months that the ape was considerably superior to the child in responding to human words. She began to react distinctively to separate vocal stimuli within a few weeks after she had entered the human environment."<ref>{{Cite book |last=Kellogg |first=W.N. and L.A. |title=The Ape and the Child: A Study of Environmental Influence Upon Behavior |date=1933 |publisher=Whittesley House |edition=First |location=New York and London |pages=289}}</ref>

The Kelloggs noted that Gua made several distinct vocalizations to communicate different needs, and, accordingly, tried to teach her to speak English words. The Kelloggs were building on Yerkes' assertion:<blockquote>It seemingly is well established that the motor mechanism of voice in this ape is adequate not only to the production of a considerable variety of sounds, but also to definite articulations similar to those of man.<ref>{{Cite book |last=Kellogg |first=W.N. and L.A. |title=The Ape and the Child: A Study of Environmental Influence Upon Behavior |date=1933 |publisher=Whittesley House |location=New York and London |pages=287}}</ref> </blockquote>But Gua did not communicate using human words. Instead of the chimp copying the humans, the Kelloggs' son Donald started copying the chimp, adopting Gua's vocalizations. Donald would use food grunts, for example, when hungry. Shortly after the Kelloggs made this observation, the experiment was discontinued. (Yerkes disapproved of Winthrop's book about the Gua experiment and had records of the project stricken from his Orange Park hub.<ref>{{Cite book |last=Halloran |first=Andrew |title=The Song of the Ape: Understanding the Languages of Chimpanzees |publisher=St. Martin's Press |year=2012 |edition=First |location=New York |publication-date= |pages=25}}</ref>)

After the Kellogg study, there were four similar research projects into cross-fostering. The most notable of these was conducted by Keith and Catherine Hayes with their [[Viki (chimpanzee)|chimpanzee Viki]]. Viki would lead people to places she wanted to go as well as move the hands of people onto objects she wanted them to manipulate. She would rarely point to objects that she wanted; instead she would make gestures. For example, when she wanted to help with ironing, she would move her hand back and forth above the ironing board. This experiment with Viki would inspire other researchers to conduct similar experiments.<ref name=":0">{{Cite journal |last=Marler |first=Peter |date=June 1999 |title=How Much Does a Human Environment Humanize a Chimp? |journal=American Anthropologist |volume=101 |issue=2 |pages=432–436 |doi=10.1525/aa.1999.101.2.432 |jstor=683228 |id={{ProQuest|198206524}}}}</ref> But when it came to teaching Viki to speak, the Hayes' efforts were only marginally more effective than others who tried to teach chimps to talk. After nearly seven years of intensive exposure to English, [[Viki (chimpanzee)|Viki]] spoke only four words, ''mama'', ''papa'', ''cup'', and ''up''.<ref name=":3">{{Cite journal |last=Gardner |first=Beatrix T. and R.A. |date=February 13, 1985 |title=Signs of intelligence in cross-fostered chimpanzees |url=https://pubmed.ncbi.nlm.nih.gov/2858873/ |journal=Philosophical Transactions of the Royal Society of London |volume=308 |issue=1135 |pages=159–176 |doi=10.1098/rstb.1985.0017 |pmid=2858873 |bibcode=1985RSPTB.308..159G |via=National Library of Medicine}}</ref><ref name=":2">{{Cite journal |last=Ekström |first=Axel G. |date=Feb 2023 |title=Viki's First Words: A Comparative Phonetics Case Study |journal=International Journal of Primatology |volume=44 |issue=2 |pages=249–253 |doi=10.1007/s10764-023-00350-1 |s2cid=257046483 |doi-access=free}}</ref>