Duncan, Robert Muir2006-07-282006-07-2819991999http://hdl.handle.net/10012/373This thesis establishes that adults use private speech, challenging Vygotsky's (1934/1987, 1978) claim that this speech form is peculiar to childhood, the equivalent of a developmental stage lasting from about three to seven or eight years of age. Related experimental research on private speech in children is reviewed, as well as the small number of previous studies on private speech in older age groups. Evidence from a series of three studies with samples drawn from an undergraduate university student population strongly supports the view that private speech is used with considerable frequency by adults. In Study 1, self-report questionnaire data indicate that adults report self-verbalizing in a variety of everyday, real-life situations. Study 2 is a microgenetic repeated-measures experiment providing evidence of short-term change in self-directed speech similar to changes reported in research with children, while participants carried out computer data entry tasks and paper-folding tasks during two sessions. Rate of speech decreased and speech preceding action increased with repetition across trials within each session, and psychologically predicative speech increased across sessions. In addition, the rate of speech was higher when participants worked on a difficult computer data entry task than on an easy one, replicating a well-established finding in research with children. In Study 3, a single-session repeated-measures factorial experiment, participants used more private speech while working on difficult tasks compared to easy tasks, and more while working on verbal tasks (arithmetic word problems and scrambled word tasks) compared to nonverbal tasks (pattern copying using blocks, and paper-folding tasks). These results establish further parallels with research on private speech in children. All participants in the two experiments used self-directed speech, but rates of speech were higher for participants who indicated awareness of self-verbalizing during the sessions when questioned afterward, than for those who denied having done so. Taken together, the findings of this research provide strong evidence that rather than being limited to childhood, private speech is common among adults as well. It is suggested that evidence of a decline in private speech use with age, from research with children, may result less from internalization of this verbal mediation than from increasing awareness of social pressure against talking to oneself, and ideas for further research investigating this suggestion are described.application/pdf10934413 bytesapplication/pdfenCopyright: 1999, Duncan, Robert Muir. All rights reserved.Harvested from Collections CanadaDoctoral Thesis