Central Washington University ScholarWorks@CWU Anthropology and Museum Studies Faculty Scholarship College of the Sciences 2002 Chimpanzee Signing: Darwinian Realities and Cartesian Delusions Roger S. Fouts Mary Lee A. Jensvold Deborah Fouts Follow this and additional works at: https://digitalcommons.cwu.edu/anthropology_museum_studies Part of the Animal Sciences Commons, Animal Studies Commons, Anthropology Commons, and the Psychology Commons This PDF includes a chapter from the following book: The Cognitive Animal Empirical and Theoretical Perspectives on Animal Cognition © 2002 Massachusetts Institute of Technology License Terms: Made available under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License https://creativecommons.org/licenses/by-nc-nd/4.0/ OA Funding Provided By: The open access edition of this book was made possible by generous funding from Arcadia—a charitable fund of Lisbet Rausing and Peter Baldwin. The title-level DOI for this work is: doi:10.7551/mitpress/1885.001.0001 35 Chimpanzee Signing: Darwinian Realities and Cartesian Delusions Roger S. Fouts, Mary Lee A. Jensvold, and Deborah H. Fouts (ASL) in Washoe’s presence (B. T. Gardner and Darwinian Realities Gardner 1971, 1974, 1989; R. A. Gardner and Gardner 1969). Truly discontinuous, all-or-none phenomena must be rare in nature. Historically, the great discontinuities In teaching sign language to Washoe [and other later have turned out to be conceptual barriers rather than cross-fosterlings] we imitated human parents teaching natural phenomena. They have been passed by and young children in a human home. We called attention abandoned rather than broken through in the course of to everyday events and objects that might interest the scientific progress. The sign language studies in chim- young chimpanzees, for example, THAT CHAIR, SEE panzees have neither sought nor discovered a means PRETTY BIRD, MY HAT. We asked probing ques- of breathing humanity into the soul of a beast. They tions to check on communication, and we always tried have assumed instead that there is no discontinuity be- to answer questions and to comply with requests. We tween verbal behavior and the rest of human behavior expanded on fragmentary utterances using the frag- or between human behavior and the rest of animal ments to teach and to probe. We also followed the behavior—no barrier to be broken, no chasm to be parents of deaf children by using an especially simple bridged, only unknown territory to be explored. (R. and repetitious register of ASL and by making signs Gardner et al. 1989, p. xvii) on the youngsters’ bodies to capture their attention. (R. A. Gardner and Gardner 1998, p. 297) Cross-Fostering In 1970 Washoe left Reno with companions While chimpanzees (Pan troglodytes) have great Roger and Deborah Fouts for the Institute of di‰culty adapting their vocalizations to human Primate Studies (IPS) at the University of Okla- speech (Hayes and Hayes 1951; Hayes and Nis- homa in Norman. The Gardners began a second sen 1971), they can freely move their hands, cross-fostering project with four other infant meaning that a gestural language is well suited to chimpanzees. Moja, Pili, Tatu, and Dar were their abilities. R. A. and B. T. Gardner recog- born in American laboratories and each arrived nized this in their sign language studies with in Reno within a few days of birth. Moja arrived young chimpanzees. In 1966, the Gardners in November 1972 and cross-fostering continued brought 10-month-old Washoe to the University for her until the winter of 1979 when she left of Nevada-Reno when they began their cross- for IPS. In 1980, Washoe and Moja moved with fostering study. The Gardners described this the Fouts to the Chimpanzee and Human Com- approach as follows: munication Institute (CHCI) on the campus of Central Washington University in Ellensburg, Cross-fostering a chimpanzee is very di¤erent from Washington. Tatu arrived in Reno in January keeping one in a home as a pet. Many people keep pets 1976 and Dar in August 1976. Cross-fostering in their homes. They may treat their pets very well, and continued for Tatu and Dar until May 1981, they may love them dearly, but they do not treat them when they left to join Washoe and Moja in like children. True cross-fostering—treating the chim- Ellensburg. Pili arrived in Reno in November panzee infant like a human child in all respects, in all living arrangements, 24 hours a day every day of the 1973 and died of leukemia in October 1975. year—requires a rigorous experimental regime that has The size of the chimpanzees’ vocabulary, rarely been attempted. (R. A. Gardner and Gardner their responses to Wh- questions (where, why, 1998, p. 292) when etc.), number of utterances, proportion of phrases, variety of phrases, length of phrases, The Gardners and students in the cross-fostering complexity of phrases, and inflection all grew project used only American Sign Language R. S. Fouts, M. L. A. Jensvold, and D. H. Fouts 286 Figure 35.1 Number of phrase tokens. throughout 5 years of cross-fostering (R. A. second month. From this record we plotted the Gardner et al. 1992; B. T. Gardner and Gardner growth of Loulis’s phrases. A phrase is two or 1974, 1989, 1998). ‘‘Washoe, Moja, Pili, Tatu, more di¤erent signs within two utterance boun- and Dar signed to friends and strangers. They daries. Utterance boundaries are defined by a signed to each other and to themselves, to dogs pause marked by a relaxation of the hands with- and to cats, toys, tools, even to trees’’ (R. A. in the signing area, or dropping the hands from Gardner and Gardner 1989, p. 24). Signing was the signing area altogether. The observer indi- a robust behavior in the chimpanzees. cated utterance boundaries in the field records with a slash. Reiteration, where a sign is repeated Cultural Transmission for emphasis, did not meet the requirement for a phrase in that it did not contain two di¤erent At CHCI we continued to explore how the signs. chimpanzees acquired signs and used them to Phrase tokens provide information on the fre- communicate with humans and each other. The quency of all phrases that appeared in a year. first of these studies began in 1978. In 1979, YOU CHASE and CHASE YES are examples Washoe adopted a 10-month-old son, Loulis. To of two di¤erent phrase tokens. When Loulis show that Loulis would learn signs from Washoe signed ME ME GOOD GOOD once on March and other signing chimpanzees without human 1, 1984 and ME ME GOOD GOOD once on intervention, we restricted human signing when May 28, 1984, this was counted as two tokens. Loulis was present except for seven specific signs, Figure 35.1 shows the total number of phrase WHO, WHAT, WHERE, WHICH, WANT, tokens recorded for Loulis each year. Loulis’s SIGN, and NAME. Humans used vocal English pattern is similar to that of Moja in figure 2 of B. to communicate in his presence. Loulis began to T. Gardner and Gardner (1998). sign in 7 days; at 15 months of age he combined We grouped phrase tokens into types accord- signs; and at 73 months of age his vocabulary ing to the signs that they contained regardless of consisted of 51 signs (R. S. Fouts 1994; R. S. the order of the signs in the utterance. For exam- Fouts et al. 1982, 1989). ple, all phrases that contained the signs THAT Human observers maintained written records HURRY, HURRY THAT, and THAT THAT of Loulis’s signing and behavioral development. HURRY HURRY THAT THAT were the same We used all of the records from his tenth month phrase type containing the two signs HURRY (the first month of the project) to his seventy- and THAT. This provides information on the Chimpanzee Signing 287 Figure 35.2 Number of phrase types: two sign phrases. Figure 35.3 Number of phrase types: three or more sign phrases. variety of phrases that Loulis produced. Figure acquisition of phrases is particularly impres- 35.2 shows the total number of phrase types re- sive since it occurred in the absence of human corded for Loulis each year. After the third year signing and his only models were other signing of the project, Loulis showed a steady increase in chimpanzees. the variety of his phrases. This pattern was simi- lar to that of Moja, Tatu, Pili, and Dar in figure Remote Videotaping 3 of B. T. Gardner and Gardner (1998). Figure 35.3 shows the development of phrase types with In June 1984, the restriction on signing around three or more signs for Loulis. An example is Loulis ended and we turned our attention to HURRY YOU TICKLE. After the fourth year recording Loulis’s use of signs by remote video- of the project, there was a sharp increase in the taping, a technique that allowed the behavior of variety of Loulis’s three or more sign phrases. the chimpanzees to be recorded with no humans Loulis’s phrase development paralleled that present. In the original method, three cameras of the cross-fostered chimpanzees. Like human were mounted in a chimpanzee enclosure, with children, the development of phrases grew grad- each focused on part of the enclosure. Later a ually in Loulis and the cross-fostered chimpan- fourth camera was added. The cameras were zees (B. T. Gardner and Gardner 1998). Loulis’s attached to television monitors and to a video- R. S. Fouts, M. L. A. Jensvold, and D. H. Fouts 288 cassette recorder (VCR) in another room away ance that refers to an object or event that is not from the chimpanzees.