Abstract

In constructing a speculative scenario for the evolution of language (Place forthcoming), I take it as axiomatic that before human beings developed the ability to communicate vocally, they communicated with one another by means of some form of sign language whose primary function was to organize the cooperative social activities ivolved in hunting ang foraging. In such a language the signs wold be entirely iconic, that is to say they would function as signs entirely by virtue of a resemblance between the sign and the object or movement it stands for. There would be no selective pressure to develop symbolic signs where the connection between the sign and what it stands for is purely arbitrary. However, studies of sign languages in general (Frischberg 1979) and of the homesigning developed by isolated deaf individuals in particular (Kuschel 1973) show that although the incidence of arbitrary symbols is much reduced as compared with vocal language, they are very much more common than would be predicted on this hypothesis. The explanation of this finding seems to be that AFTER the development of vocal language when the selective pressure for the development of symbolic signs was much greater due to the limited possibilities of representing objects and movements iconically, a genetic mutation occurred the effect of which was to give human beings a strong preference for communication by means of arbtirary symbols. The evidence for this mutation comes froma quite different source, from experimental studies that have been conducted in recent years within the behavior analytic paradigm on the phenomenon known as "stimulus equivalence" (Sidman 1971; 1986; 1990; Sidman and Tailby 1982). Associated with this is the work that has been done at the University of Wales, Bangor, (Dugdale and Lowe 1990; Horne and Lowe 1996) on the link between the emergence of stimulus equivalence responding in the child of 2-3 years and the so-called "naming explosion" observed by developmental psychologists which appears to occur at the point in development at which language "takes off" in the human child and fails to do so in its closest primate relatives.

 Conference site: http://www.infres.enst.fr/confs/evolang/