THe NYT has a piece on language development and its relation to kids' lexicons (here). The reported study "debunks" an earlier one that tried to track vocal size and language proficiency at 3:
"It has been nearly 20 years since a landmark education study found that by age 3, children from low-income families have heard 30 million fewer words than more affluent children, putting them at an educational disadvantage before they even began school."
The new study insists that quality is more important than quantity:
"The quality of the communication between children and their parents and caregivers, the researchers say, is of much greater importance than the number of words a child hears."
What's "quality" mean? Well it seems that language proficiency is better if adults talk to their kids meaningfully:
A study presented on Thursday at a White House conference on “bridging the word gap” found that among 2-year-olds from low-income families, quality interactions involving words — the use of shared symbols (“Look, a dog!”); rituals (“Want a bottle after your bath?”); and conversational fluency (“Yes, that is a bus!”) — were a far better predictor of language skills at age 3 than any other factor, including the quantity of words a child heard.
So, lots of words without "shared symbols," "rituals," or "conversational fluency" is not optimal. Here's what Hirsch-Pasek says:
“It’s not just about shoving words in,” said Kathryn Hirsh-Pasek, a professor of psychology at Temple University and lead author of the study. “It’s about having these fluid conversations around shared rituals and objects, like pretending to have morning coffee together or using the banana as a phone. That is the stuff from which language is made.”
It's the last sentence that bothers me. Why? Because it suggests that there is some interesting linguistic relation between how words are presented to kids and the G that develops. Let me be clear, I can imagine that interacting with your kid in "meaningful" ways could have an impact on G development. But this is not a fact about language or FL, but a fact about human interactions. Meaningful interactions matter all over the place: I also believe that students who think teachers care about them do better at learning than students who think they don't. Nor is it species specific. Chomsky in Aspects (p. 34) cites Richard Held as showing that "stimulation resulting from voluntary activity…is a prerequisite to the development of visual space, although it may not determine the character of this concept… [and] it has been observed (Lemmon and Patterson 1964) that depth perception in lambs is considerably facilitated by mother-neonate contact, although again there is no reason to suppose that the nature of the lamb's "theory of visual space" depends on this contact."
So too with "quality talk."
In fact, we suspect that such talk is not particularly efficacious as language growth can take place well without it. Indeed, in some cultures one doesn't talk to kids because they don't talk back (thanks Paul). Middle class americans talk to their kids, and their dogs and their cats and even their cars (especially if it has a Navi system). These don't develop anything language like despite all the quality discussion. So whatever is going on here, this interaction is at best accidental and is not "the stuff from which language is made."
I have nothing against interacting nicely with our younger non-fluent conspecifics. I have indulged in this practice myself. However, I am pretty sure that it tells us nothing about our distinctive human capacity to acquire and use a G or a lexicon for that matter. It tells us that kids do better when emotionally supported (if it tells us even that). So talk to LADs, and nuzzle a lonely lamb, but don't be fooled into thinking that how you do this really tells us much about the inner workings of FL.