Answers are grounded in this paper and cite their sources.
Follow-up studies show that prognosis is poor for autistic children who fail to develop speech by age five. An operant conditioning speech training program established a basic speaking vocabulary in a four-and-a-half-year-old nonverbal autistic boy. This conditioned speech later began to acquire the characteristics of meaningful language.
No takes yet. Share an insight, caveat, or question.
Frank M. Hewett (1965) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: