The first studies of language acquisition by the child described mainly the developmental stages of this specific human ability From Piaget (1923) to Brown (1973), authors were interested mostly in the different formal aspects of the acquisition: for example, the age of onset, total amount of language at any age, mean length of utterance, and emergence of grammar. These studies considered the abilities of each child as representative of the general linguistic abilities of the human species at this ontogenetic stage.
More recently, new trends have appeared, where language is studied in a more pragmatic way: it is considered as a means, at each developmental stage, for a child to elicit real communicative interactions. Thus, while admitting that the general stages of language development are alike in any child (Locke & Snow, Chapter 14) such an approach to the development of communication implies integrating various aspects that are usually considered separately by different researchers.
On the one hand, to consider the emerging linguistic skill as part of the larger phenomenon of communication implies integrating the analysis of the linguistic competence of a child at a given stage with that of previous stages, in particular with babbling. It implies also the integration of other communicative behaviors: for example, approaches, emotional addresses, and object exchanges. It can be hypothesized that, when a child is communicating, it is both acquiring the human language and developing its personal communicative style with human beings.