Electronic Theses and Dissertations

Date

2023

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Communication Sciences & Disorders

Committee Chair

D. Kimbrough Oller

Committee Member

Naomi Eichorn

Committee Member

Robert Cohen

Committee Member

Yonghong Jade Xu

Abstract

This dissertation compared gestural and vocal communication in the development of language in early infancy/childhood. The work also has implications regarding the evolution of language. Since language is primarily vocal it might be assumed vocalization is the predominant communication in infancy and that the evolution of language also depended primarily on the evolution of vocal capabilities. But the primary literature actually favors primarily gestural language origins. The present work contradicts the primary literature. Study 1 examined rates of gesture and speech-like vocalizations, or “protophones”, in the first year of life. Infant protophones occurred more than 5 times more often than gestures. Gaze direction toward a possible receiver was rare for both vocalization and gesture, but vocalizations occurred more frequently with directed gaze than gestures. The results thus contradict the widespread belief that early language is founded primarily in gesture, and the gaze directivity data add to the contradiction. Gesture is useless as communication if no one is looking. Yet vocalization, which can communicate without listeners watching, was significantly more often accompanied by gaze directed to caregivers than gesture was. It appeared, therefore, that a greater proportion of vocalizations than gestures in the first year may have been intended as communications. Study 2 evaluated how often children produced gestures and vocalizations (i.e., protophones and words) in the second year of life (at 13, 16 and 20 months). As with Study 1, the results suggested vocalization played a much more important role in language learning than gesture. Gestural activity occurred much more often in the second year than in the first, but vocalization still exceeded gestural acts by more than a factor of two. More importantly, the vast majority of gestures were confined to Universal acts that are not symbolic, but rather constitute deictic indicators (pointing and reaching) that can serve no other communicative functions. In contrast, words or signs can reference abstract categories and can serve a vast array of communicative functions. Words, however, outnumbered signs by a factor greater than 11 across the data at all ages and by a factor of 21 at 20 months.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest

Notes

Open Access

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