If you don’t follow the blog of Dorothy Bishop, start doing it right now. Her latest blog post is on the topic of what influences the quality of child language and I’m so tempted to just copy the text. But I won’t.

I only want to use the quote Dr. Bishop finishes with:

People seem to have little difficulty in accepting the modifiability of “environmental” effects on human development. If a child has had bad teaching in mathematics, it is accepted that the resulting deficiency can be remedied by extra good teaching the following year. But any suggestion that the child’s mathematical deficiency might have a genetic origin is likely to be greeted with something approaching despair: if it is in the genes “it is written”, it is “determined” and nothing can be done about it: you might as well give up attempting to teach the child mathematics. This is pernicious rubbish on an almost astrological scale ….. What did genes do to deserve their sinister juggernaut-like reputation? Why do we not make a similar bogey out of, say, nursery education or confirmation classes? Why are genes thought to be so much more fixed and inescapable in their effects than television, nuns, or books? 
Richard Dawkins (1982) The extended phenotype, Oxford University Press (p. 13)

Or wait, this quote is maybe as important:

“My suggestion is that rather than denying the reality of genetic effects, we should be conducting research to find out what kinds of input are most effective for children who are at genetic risk. It is possible that rather than more language input, they may do best with a different kind of language input, specifically tailored to take into account their cognitive strengths and weaknesses. We are a long way from understanding how best to do this, and meanwhile, ingenious and dedicated practitioners are working hard to tackle the very real problems that some children experience. My message is simply that to lay the blame for these difficulties at the door of parents, and to anticipate that problems can be readily overcome by encouraging parents to talk more to their children may be oversimplistic.”