Individual Differences

Children vary not only in the rate of language development but also in the route. Those developing typically may exhibit as much as thirty months' variation in language development by 42 months of age (Wells, 1985). Individual developmental differences are related to differences in intellect, personality, and learning style; ethnicity and the language of the home; socioeconomic status; family structure; and birth order. In general, these relationships are very complex, not simply cause and effect. Some factors, such as intelligence, may be much stronger than others. Socioeconomic factors alone, for example, may have little overall effect on rate of language development (Wells, 1985). There may be more differences within socioeconomic classes than between them. In contrast, birth order or position in the family has a significant effect on early language development. Single children have a greater opportunity to communicate with adults than do children with several siblings and thus develop language more quickly. Twins may spend a great deal of time talking to each other with resultant multiple phonological errors (Dodd & McEvoy, 1994).

The learning style of a child also affects language learning to some extent. In general, an active, outgoing child is more likely to learn language more rapidly than a placid, retiring child (Wells, 1985). The former is more inclined to join in and to communicate with whatever means are available, fostering learning the language code.

Individual styles of learning are evident very early (Hampson & Nelson, 1993). Different types of maternal stimulation also affect children in diverse ways. Some toddlers attend to symbols while others prefer paralinguistic and nonlinguistic elements. Maternal behaviors may be in response to these differences rather than a cause of them as is often assumed.

Considering solely the rate of language learning may be misleading without accompanying information on the route. For example, some children exhibit advances in expressive language use, while others who seem somewhat delayed in this area exhibit superior comprehension skills.