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Miles, L. W. & S. E. Harper (1994) "Ape language" studies and the study of human language origins. in Hominid Culture in Primate Perspective, by Quiatt, D. D. & J. Itani (eds). University Press of Colorado. pp253-278

Author of the summary: Jim Davies, 1998, jim@jimdavies.org

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This paper describes what apes can do with language and talks about what that might tell us about our evolutionary ancestors' abilities.

p253: Studies of ape language use sheds light on early hominid language use. It suggests that they had:

  1. A flexible, basic semantic communications system with moderate levels of reference
  2. low levels of perspective-taking, imitation and sequential organization and protosyntax
Grammar may have come later in the evolutionary process.
If the linguistic and cognitive abilities of enculturated apes can be only matched by late hominids, it shows the importance of culture to human evolution.

p254: as of 1994, about 20 apes received some degree of language training. People still argue about apes' use of grammar, but by and large there is agreement that apes can use symbol systems (Cheney and Seyfarth 1990).

p255: The modern focus of ape language research is to compare to language development in children, rather than to adult language ability.

p257: Project Chantek is the only anthropologically oriented ape language research effort. Using the research to understand human evolution has been a goal of the project from the outset.

p258: Researchers who tried to use an artificial language and limit the cultural aspect turned to more humanlike rearing and found more success.

APE # of signs reported learned
Nim 125
Washoe 133
Moja 168
Tatu 140
Dar 122
Loulis 70
Sarah 130
Chantek 150
Koko 224
(a deaf child of three years) 132
Most apes are at about 150, a deaf child at age three is at about 130. Signing apes achieve vocabularies of three year olds.

p259: Many of the signs that apes have difficulty with are the same as those that children have difficulty with (e.g. pronouns, abstract concepts, nontouch signs)

Daily, however, Chantek uses about 50 signs.

p260: Attempts to get apes to speak met with failure.

p262: All apes raised in human culture can refer to things not present.
All signing apes have the ability to create signs. Washoe, Chantek (5 new signs), and Koko (4) have all done this.

p265: Apes rarely engage in symbolic play.

p266: Many apes sign to themselves when nobody else is around.

Other than Nim, signing apes utter strings of length 2 to to four symbols long. This is about the same as a 2 or 3 year old child.

All of the apes produce sign combinations that they have not heard before.

p269: General ape language like 2 year old humans, other cognition like 3-4 year olds.

p270: Reseaerchers such as Chomksy think that language developed only in humans only very recently. But "Given the morphological, neural and behavioral factors involved in that very complex phenomenon of human language, it is highly unlikely that such a combination of events happend suddenly and synchronically. (Bates, Thal, and Marchman 1991)"

p275: Hypothesis: The earliest hominid ancestors have communicative abilities similar to present day apes in the wild. Later hominids were like modern enculturated apes. In the upper Paleolithic, they developed new ways to communicate due to selective pressure to handle more symbols.

Summary author's notes:

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