ABSTRACT
This chapter examines the rise of linguistic or communicative habits in the child and explores the development of the self. The new manipulatory capacity in turn led to the development of tools and mechanical devices for further control of the environment. The posture of sexual intercourse was changed, as were the bodily contacts of mother and young in nursing. But of particular importance was the release of the mouth and larynx from too immediate concern with food gathering, which made possible the further development of vocalization. The development of vocabulary and capacity in language is evidently related to a number of other factors: sex, intelligence, motor ability, socioeconomic status and cultural level, the place of companions and associates, and the exposure to bilingual situation. L. M. Terman found that girls of superior intelligence in the early months of learning to talk outstrip boys of similar intelligence in the use of short sentences.
