Music & Language Studies

Petitto, Laura Ann. “On the biological foundations of human language,” in Emmorey et al, Eds., The Signs of Language Revisited. [CITY?]: Lawrence Erlbaum. 2000, 449-473.

The author, who as an undergraduate at Columbia University had been part of an ape-language experiment with the West African chimpanzee, Nim Chimpsky, sets down the task:

Our question concerned whether aspects of human language were species specific, or whether human language was wholly learnable from environmental input. (450)

She adds:

All chimpanzees fail to master key aspects of human language structure, even when you give them a way to bypass their inability to speak—for example, by exposing them to other types of linguistic input such as natural signed languages. This fact raised the hypothesis to me that humans possessed something at birth in addition to the mechanisms for producing and perceiving speech sounds that aided them in acquiring natural language.

In this article, she seeks in particular to challenge the notion that

evolution has rendered the human brain neurologically “hardwired” for speech (Liberman & Mattingly, 1985, 1989; Lieberman, 1984). (452)

She contends that

If, as has been argued, very early human language acquisition is under the exclusive control of the maturation of the mechanisms for speech production and speech perception (Locke, 1983; Van der Stelt & Koopmans-van Bienum, 1986), then spoken and signed languages should be acquired in very different ways. (452)

She proceeds to outline a great many experiments involving deaf children of deaf and hearing parents, hearing children of deaf parents, English, French, ASL (American Sign Language), LSQ (Langue des Signes Québécoise).

In describing one part of the study, involving hearing children exposed only to sign languages, she notes the suprising result that

These babies achieve all linguistic milestones on a normal maturational time table. If early human language acquisition were wholly determined neurologically by the mechanisms for speech production and reception, then these hearing babies raised without systematic spoken language stimulation should show atypical patterns of language acquisition. Instead, all of these groups of hearing babies produced manual babbling, first signs, first two-signs, and other milestones, at the same time as is seen in all other children, be they hearing acquiring speech or Deaf acquiring sign. (456)

She asks:

Might the occurrence and developmental timing of this behavior in all infants suggest something about the “ready-state” nature of the human body to express language from multiple pathways? (462)

Then proceeds to outline her theory that

there is a biological “equipotentiality” of the spoken and signed modalities to receive and produce natural language. (462)

At the end of this thoroughly enjoyable, greatly detailed, and forcefully argued piece, she concludes:

the present findings have led me to propose a new way to construe human language ontogeny. Rather than being exclusively hard-wired for speech or sound, the young of our species are initially hardwired to detect aspects of the patterning of language. I suggested here that this initial sensitivity is to aspects of its temporal and distributional regularities initially corresponding to the syllabic and prosodic levels of natural language organization. (470)

References

LIBERMAN, Alvin M., and Ignatius G. Mattingly. (1985) “The Motor Theory of Speech Perception Revised.” Cognition 21 (1985): 1-36.

–. (1989) “A specialization for speech perception.” Science 243 (4890): 489-494.

Lieberman, P. (1984) The biology and evolution of language. Cambridge, MA: Harvard University Press.

Locke, J. L. (1983). Phonological acquisition and change. New York: Academic Press.

Van der Stelt, J. M. & Koomans-van Bienum, F. J. (1986). “The onset of babbling related to gross motor development.” In Lindblom & Zetterstrom (Eds.), Precursors of early speech. New York: Stockton Press, 163-173.