This view of the primacy of cognitive development is supported by Slobin (1971, 1973), who presents evidence from studies of bilingual children. According to Slobin, when a child will learn to express a given conceptualization in language should be determined by two things: the difficulty of the underlying conceptualization and the complexity of the linguistic form necessary to express it. Bilingual children, if they do first acquire the conceptualization and then learn to express it, should be able to express it in the language in which it is linguistically less complex before being able to express it in the language that requires a more complex form. This is precisely what Slobin found.

We are subscribing to the position that cognitive development precedes languaging ability. We believe that cognitive development begins as a result of sensori-motor activity and that this development precedes any effect of language. Sensor i-motor activity also forms the conceptual base for the beginning of languaging.

After the development of sensori-motor intelligence and the beginning of languaging, the child continues to attain more advanced schemata and states of equilibrium. He makes greater use of symbols and abstractions, masters the more complex aspects of language, greatly increases his vocabulary, and learns new information that gets stored in memory. Once languaging has undergone some development, it may play an important role in further cognitive development. Cazden (1972) points out that words tend to integrate otherwise separate features. For example, when a child learns that a group of objects all have the same name, he then searches for similarities in them which he would not search for if they had different labels. Gagne notes that "the preavailability of language (verbal chains) has been shown to make considerable differences in the acquiring of concepts by children" (1965, p. 134).

In the present model, then, we consider that, in the developmental sequence, the child first develops a conceptual base (ie., some types of ideas or concepts), and later acquires the ability to exchange concepts with others through the use of rules for selecting and sequencing conventionalized signs. The process of using these signs and rules we are calling "languaging." Exactly what the signs and rules are we do not know, especially in the case of non-spoken language (complex gestural sequences, bodily movements that communicate subtly, paintings that represent complex internal conceptualizations, etc.)

We do know a little about the signs and the rules for sequencing these signs in the case of spoken language, and so the next section will discuss the child's acquisition of languaging ability. Since this is a very complex topic about which books have been written, our treatment will necessarily be brief. It is meant only to provide a little more flesh for the skeletal model we are describing.