The anthropological linguistic stream has consisted chiefly of data elicited from adults in different societies on how they address children, and a limited amount of naturalistic observation in those societies. Substantial studies of this kind go back as far as the 1940s (with more limited studies even earlier) […]. This stream has tended to focus on phonological and lexical features of BT and on displaced and extended uses of BT (e.g., reporting children’s speech, to pets, between lovers).
- Ferguson-DeBose (1977), Pag. 102