Yerkish is an artificial

language Language is a structured system of communication that consists of grammar and vocabulary. It is the primary means by which humans convey meaning, both in spoken and signed language, signed forms, and may also be conveyed through writing syste ...

developed for use by non-human

primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...

s. It employs a keyboard whose keys contain ''lexigrams'',

symbol A symbol is a mark, Sign (semiotics), sign, or word that indicates, signifies, or is understood as representing an idea, physical object, object, or wikt:relationship, relationship. Symbols allow people to go beyond what is known or seen by cr ...

s corresponding to objects or ideas. Lexigrams were notably used by the

Georgia State University Georgia State University (Georgia State, State, or GSU) is a Public university, public research university in Atlanta, Georgia, United States. Founded in 1913, it is one of the University System of Georgia's four research universities. It is al ...

Language Research Center to communicate with

bonobo The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee (less often the dwarf chimpanzee or gracile chimpanzee), is an endangered great ape and one of the two species making up the genus ''Pan (genus), Pan'' (the other bei ...

s and

chimpanzee The chimpanzee (; ''Pan troglodytes''), also simply known as the chimp, is a species of Hominidae, great ape native to the forests and savannahs of tropical Africa. It has four confirmed subspecies and a fifth proposed one. When its close rel ...

s. Researchers and primates were able to communicate using lexigram boards made in up to three panels with a total of 384 keys.

Context

The Yerkish language was developed by Ernst von Glasersfeld and used by Duane Rumbaugh and Sue Savage-Rumbaugh of Georgia State University while working with primates at the Yerkes National Primate Research Center of

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. Primates were taught to communicate by means of a lexigram board, a computerized array of keys labeled with lexigrams. Von Glasersfeld coined the term "lexigram" in 1971, created the first 120 of them, and designed the grammar that regulated their combination. This artificial language was called Yerkish in honor of Robert M. Yerkes, the founder of the laboratory within which the lexigrams were first used. The first ape trained to communicate in Yerkish was the chimpanzee Lana, beginning in 1973 within the context of the LANA project. Researchers were hoping Lana would not only interpret the Yerkish language, but would also participate in communication with others through this newfound language.

Design considerations

Lexigram concept

Research leading to 1973 suggested chimpanzees could acquire and retain symbolic use of visual items. In an attempt to structure the use of symbols as language, Yerkish formalized the use of the ''lexigram'', a graphic design which represents a word but is not necessarily indicative of the object to which it refers. Each lexigram is designed to be semantically and syntactically ''unequivocal'', a conscious effort to reduce the ambiguity of English. For example, the use of color conveys semantic code, with red lexigrams identifying ingestible items like food and drink, blue lexigrams designating activities, and violet lexigrams representing animate beings like humans. Existing technical limitations guided lexigrams to be constructed by 9 single elements which could be combined by being superimposed. The lexigram for "juice", which is red in color, is a combination of elements 1 (a vertical line), 5 (a circle), and 9 (a wavy line). Von Glaserfeld created approximately 150 of the first lexigrams in the Yerkish language.

Interface

Keyboard

A lexigram keyboard was created for Lana with each key representing various nouns or verbs such as food, eat, apple, drink, etc. Von Glaserfeld used 25 of them in his initial experiment with Lana. Each of these keys was 1 x 1 inch and lit up when pressed. After pressing a certain key, the corresponding item would emerge from a food dispenser placed next to the keyboard, and through a series of experiments, researchers hoped that Lana would learn to interpret what each key would correlate to and learn to meaningfully communicate her requests.

Notes

References

# Rumbaugh, D. M. ed. (1977) ''Language Learning by a Chimpanzee. The LANA Project''. New York, Academic Press # von Glasersfeld, E., Department of Psychology, University of Georgia
The Yerkish language for Non-Human Primates
. American Journal of Computational Linguistics, 1974, 1. # Bettoni M. C. (2007
The yerkish language: From operational methodology to chimpanzee communication
Constructivist Foundations 2(2-3): 32–38. # {{list of writing systems Constructed languages Animal rights Animal communication Constructed languages introduced in the 1970s 1971 introductions Primatology