Child Language Development Experts Agree

Child Language Development

Experts agree that language formation, like many aspects of child development, is consistent with the classic "Nature through Nurture" theory. That is, all children have an in-built biological capacity to learn language within the context of environment. Since different environments support language acquisition in different ways and to various extents, there are wide individual and group variations in the rate and trajectory of language development (Hoff, 2006). The number of factors reported in developmental psychology literature as influential in language development is overwhelming. They range from the ubiquitous (e.g. culture, socio-economic status, and maternal responsiveness) to the seemingly trivial (e.g. birth order, television, and age of caregiver; Hoff, 2006).

While many of these environmental factors are relatively stable (e.g. ethnicity, birth order, socio-economic standing, child factors), some of them are amenable for control or intervention so as to positively impact language development in children. Of note is the influence of parental behavior, especially in providing the right foundation and communication setting to enhance the language learning process. This paper will focus on two parent-controlled factors, specifically the quality and quantity of their vocabulary or lexical input. The highlight of the following discussion is on vocabulary formation as an indicator of language development since it is widely recognized as powerfully linked to reading comprehension and academic success (Weizman and Snow, 2001). In light of the parental influences discussed, a simple intervention program to improve child vocabulary development is also proposed.

Children rely on parents for their early language experience. Since parents differ in the experience they provide, it is not surprising that young children vary in vocabulary size and rate of vocabulary development during the early years. The quality and quantity of lexical input of parents are recognized as two major influences in vocabulary development among children. Vocabulary formation starts with slow word formation followed by a prolonged, accelerated period of word learning between 14 and 22 months (study among middle-income family children; Goldfield and Reznick, 1990 in Pan et al., 2005). By three years of age, the mean cumulative recorded vocabulary for children is between 500-1000 words, with socio-economic status (SES) accounting for 36% of the variation (Hart and Risley, 1995, in Hoff, 2006).

Many studies suggest that the amount of language input to which children have been exposed during the early years is the major factor explaining differences in the vocabulary size and rate of vocabulary growth among young children. It is reported that among middle-class children aged 14-26 months, the best predictor of vocabulary rate growth is maternal word density input (Huttenlocher et al., 1991, in Weizman and Snow, 2001). An important observation that impacts the influence of maternal word input quantity is that high SES mothers talk to their children more than do lower SES mothers (Ho?, Laursen, & Tardif, 2002 in Hoff, 2006). Concrete data show that by age three, children of professional parents hear twice as much words as working class children and four times as much words as welfare children (Hart and Risley, 1995, in Weizman and Snow, 2001). Quite expectedly, children with the most number of words heard are also the ones with the largest vocabularies (Hart and Risley, 1995, in Weizman and Snow, 2001). Many studies confirm that children from working class backgrounds have smaller and less diverse vocabulary than their middle-class counterparts (Ho?, Laursen, & Tardif, 2002 in Hoff, 2006; Hoff-Ginsberg, 1991 in Hoff, 2006).

That being said, it is possible that the quantity of word input alone may not be the only factor predicting vocabulary outcomes in young children. Larger vocabulary input does not necessarily equate to richer and more diverse vocabulary, one that is usually brought about by consistently hearing low-frequency words (i.e. words that neither fell within nor were derived from the 3000 most common words; Weizman and Snow, 2001). This point is important because it potentially eliminates the limitations brought about by lower maternal SES or educational background on a child's vocabulary development.

For instance, a study on five-year-old children from low socio-economic backgrounds shows that it is not difficult at all to introduce "sophisticated" words like "tusks," "cholesterol," and "vehicle" in mother-child interactions during normal daily activities like mealtime, book reading, and playtime (Weizman and Snow, 2001). Further, even if the amount of sophisticated words consists only 1% of the total maternal verbal input, it nonetheless predicts improved second grade vocabulary outcomes among the subjects, over and above the quantity of lexical input (Weizman and Snow, 2001). These results are quite striking considering that the mothers come from non-professional backgrounds and had no more than 12 years of schooling on average. Another study on low-income mother-child dyads shows that the rate of vocabulary production is also positively influenced by early exposure to diverse words. In particular, children whose mothers consistently used more varied vocabulary had faster and more linear growth in child vocabulary production between 14 and 36 months than children whose mothers consistently used less varied vocabulary (Pan et al., 2005). These findings support the contention that maternal speech quality has powerful benefits in child language acquisition.

A striking feature of the vocabulary development studies recently described is the presence of a loving, supportive environment in which they occur. In other words, the benefits of qualitative and quantitative vocabulary input can be fully realized if they occur in the context of instructive and helpful interaction. For instance, studies show that children who are exposed to sophisticated vocabulary under supportive settings such as book reading or joint attention episodes learn vocabulary faster and better than other children (Feitelson et al., 1993; Tomasello, 1992; and Hayes & Ahrens, 1988 in Weizman and Snow, 2001). Joint attention involves mutual engagement and some mothers pursue this more than others by being responsive to their children's vocalizations prior to and during speech (Hoff, 2006). There is wide evidence that children with responsive mothers begin to talk sooner and reach a landmark vocabulary score earlier than those with less responsive mothers (Tamis-LeMonda et al., 1996 and Bornstein, Baumwell, & Damast, 1996, in Hoff, 2006).

The issues raised above indicate that vocabulary enrichment in children is achievable regardless of socio-economic background and other previously thought of maternal limiting factors.

In fact, an intervention plan aimed at improving child language development (vocabulary, in particular) can be designed by focusing on parental behavior alone. There are simple ways and readily available opportunities for parents to significantly impact their children's vocabulary growth:

First, parents should start veering themselves away from the popular notion, "the simpler, the better" as far as conversations with children are concerned. As previously shown, there is evidence suggesting that engaging pre-school children in sophisticated words during seemingly ordinary activities like play time and meal time can predict positive vocabulary outcomes later in school (Weizman and Snow, 2001). For instance, parents can use the word "vehicle" as an all-encompassing word to describe transport toys like car, train, and truck during playtime. Or perhaps during extended mealtimes, they can point to their children's healthy favorite food (e.g. fruit) as being rich in "vitamins" and to the unhealthy ones (e.g. French fries) as being rich in "cholesterol."