“…For what the research with Sherman and Austin demonstrates is how verbal behavior -that is, what we describe as "verbal behavior" -"emerges from and with nonverbal behavior, and as it does, it provides for a new means of coordinating interindividual object-oriented behaviors" (Savage- Rumbaugh 1986, p. 31). On this line of thinking, the ontogeny of language skills lies, not in a genetic blueprint for "encoding" and "decoding" "mental states" or "representations" using a "generative" system of sounds or signs, nor in a sudden mental shift from "indexical" to "symbolic" comprehension, but rather, in "interindividual interactions [that] come to be coordinated through the use of words" (Savage- Rumbaugh 1986). The psychological problem we are then left with on the dynamic systems approach is: What made Sherman and Austin's communicative development possible?…”