Use of language and controversy Francine Patterson published a few peer-reviewed studies on her work with Koko in the late 1970s. She demonstrated that Koko was able to communicate using a number of signs adapted from American Sign Language. Gorillas have thick, stubby fingers and hands that move differently than humans, so Koko was unable to make some ASL signs. Francine Patterson used the term "Gorilla Sign Language" to refer to Koko's adaptations. Patterson reported that Koko invented new signs to communicate novel thoughts. For example, she said that nobody taught Koko the word for "ring", so Koko combined the words "finger" and "bracelet", hence "finger-bracelet". This type of claim was seen as a typical problem with Patterson's methodology, as it relies on a human interpreter of Koko's intentions. In 1979,
Herbert S. Terrace published the negative results of his
Nim Chimpsky study, which presented evidence that Koko was mimicking her trainers. Terrace's article ignited intense debate over the ape language experiments (see "Scientific criticism" below), culminating in the 1980 "
Clever Hans" conference that mocked the other researchers involved. Funding for the ape language experiments disappeared seemingly overnight. While other scientists severed ties with their apes after funding dried up, Patterson maintained responsibility for Koko. (Most of the chimps who worked with Terrace, as well as with
the Gardners, were sold to medical labs for use in testing.) Though Patterson had initially defended her scientific work, she turned her focus away from science and toward securing revenue for the upkeep of Koko and Michael.
Scientific criticism Francine Patterson's published research received a variety of criticisms from the scientific community.
Herbert S. Terrace and
Laura-Ann Petitto, researchers who worked with
Nim Chimpsky, issued critical evaluations of Patterson's reports and suggested that Koko was simply being prompted by her trainers' unconscious cues to display specific signs. Terrace and Petitto questioned Patterson's interpretations of Koko's signing and her claims of grammatical competency, asking for more rigorous testing. (Terrace and Petitto reported negative results in their Nim study, which was itself criticized on methodological grounds.) Other researchers argued that Koko did not understand the meaning behind what she was doing and learned to complete the signs simply because the researchers rewarded her for doing so (indicating that her actions were the product of
operant conditioning). Another concern was that interpretation of the gorilla's conversation was left to the handler, who may have seen improbable
concatenations of signs as meaningful; for example, when Koko signed "sad" there was no way to tell whether she meant it with the connotation of "How sad." Patterson defended her research, stating that
blind and double-blind experiments had been administered to evaluate the gorillas' comprehension, that the gorillas were able to sign spontaneously to each other and to strangers without the prompting of a trainer, and that they signed meaningfully the majority of the time. Later critics noted that Patterson used Koko in deceptive ways in popular media. These concerns were echoed privately by staff at the Gorilla Foundation, where turnover was high. Some, like research assistant Anne Southecomb, expressed concerns that Patterson's exaggerated claims and "over-interpretation" undermined and disvalued their work. (Southcombe left to work with orangutan
Chantek on a research project she preferred.) Sign language expert Sherman Wilcox, for example, characterized the Foundation's edited clips of Koko making a "climate speech" as deceptive and "disrespectful of ASL". Wilcox expressed concerns that the bit would reinforce the perception that ASL is "only words and no syntax". Eugene Linden, a journalist who spent years studying apes involved in language experiments and co-wrote (with Patterson)
The Education of Koko, also expressed concerns about Patterson's practices. Linden reported that Koko's signing was more fluid and precise than that of
Washoe and other Oklahoma chimpanzees. She was also by nature less impulsive; though, like the chimps, she frequently refused to participate in language drills. When not pushed to perform or stressed by strangers, "the amount of signing by Koko seemed to me to overwhelm [Patterson's] capacity to digest and analyze it," Linden wrote. But in Linden's view, Patterson's exaggerated claims, "
bunker mentality", refusal to provide researchers access to Koko, and unwillingness to open up the data she had collected minimized Koko's impact. Ultimately, critics of Patterson's claims acknowledged that Koko had learned a number of signs and used them to communicate her wants.
Care practices criticism Former employees of The Gorilla Foundation criticized the methods used to care for Koko and her male companion
Ndume. In 2012, nine staff members including caregivers and researchers out of "roughly a dozen" resigned, and several submitted a letter to the board to explain their concerns. Former caregiver John Safkow stated that all members of the board left after the walkout, except for
Betty White. A pseudonymous source, "Sarah", told
Slate that Koko's diet included an excess of processed meat and candy, and that Koko was given a traditional
Thanksgiving dinner yearly. The source stated that the official diet they were told to give Koko was appropriate, but that Patterson would visit and feed her "chocolates and meats". Koko's weight of was higher than would be normal for a female gorilla in the wild, approximately ; the foundation stated that Koko "is, like her mother, a larger frame Gorilla."
Nipple fixation and lawsuit Like other apes raised by humans (
Lucy,
Washoe), Koko did not develop the sexual instincts of an ape raised in the wild. According to Patterson, she developed several crushes on human men. For example, Koko "maintained a near-constant vigil by the trailer window" when a favorite workman was expected to show—and blew him kisses after he arrived. Though Patterson secured male gorillas
Michael and
Ndume for Koko to mate with, she was not sexually interested in them. (As a result, Ndume was caged separately, in isolation.) Koko was reported to have a preoccupation with seeing
nipples. Shortly thereafter, a third woman filed suit, alleging that upon being first introduced to Koko, Patterson told her that Koko was communicating that she wanted to see the woman's nipples, pressuring her to submit to Koko's demands and informing her that "everyone does it for her around here." When the woman briefly lifted her t-shirt, flashing her undergarments, Patterson admonished the woman and reiterated that Koko wanted to see her nipples. When the woman relented and showed her breasts to Koko, Patterson commented "Oh look, Koko, she has big nipples." On another occasion, one of the gorilla's handlers told the woman that Koko wanted to be alone with her. When the woman went to Koko's enclosure, Koko began to squat and breathe heavily. The lawsuits were
settled out of court. When asked to comment on the matter, gorilla expert Kristen Lukas said that other gorillas are not known to have had a similar nipple fixation. (Most captive gorillas are housed in social groups with other gorillas, whose nipples are naturally exposed. Koko was unusual in living among humans and without a gorilla cohort.) A former caregiver stated that Patterson would interpret the sign for "nipple" as a sound-alike, "people", when notable donors were present. ==Later life and death==