Soderstrom – studying the impact of SES on language development

So, there was this original study called Hart and Risley. That was the authors’ names. So the Hart and Risley study was ground-breaking in a sense that it was looking at the impact of socioeconomic status on the language experiences of infants.  And the original finding was that there were differences in the quantity and the type of language exposure that infants from different socioeconomic backgrounds were exposed to and this was correlated with differences in their vocabulary development. And so this was calculated and the term was coined the 30 million word gap and its had quite an impact in our thinking about how to address social disparities. And so that was done with the research methods of the time and in fact, it was somewhat ground-breaking. I think sometimes people underestimate the amount of effort that was put into painstakingly hand transcribing all of those many hours of recording and so, you know, sometimes people criticize it was a small sample but gosh, there was years of effort that went into producing that result.  

So that was kind of a seminal finding. Since then there’s been quite a lot of research looking at the impact of socioeconomic status on the experiences and the language development of infants and there’s a general consensus that there is an impact of socioeconomic status. What is driving that is, of course, the question. And so more recently there’s been a debate that’s emerged in the field around how we characterize and how we understand the nature of children’s language experiences.  

So one of the things that’s kind of this thing that we’re trying to resolve is that on the one hand, you have this very robust set of findings about differences across socioeconomic status. On the other, you have these very strong cross-cultural differences in what’s considered sort of normative behaviour between mothers and infants. And we know of communities around the world where the idea of spending time talking directly to your children has, you know, that’s just – it’s very different. There’s the – if you measure it there’s just very little actual directed speech in these sort of one-on-one context. And at the current state of our understanding of these things there doesn’t appear to be any reason to believe that those – children from those communities are disadvantaged when it comes to language development. 

So, on the one hand, we have this robust literature that says that the amount of speech and the quality of the speech that you hear is directly tied to your vocabulary development and measures of language development. On the other we have these massive cross-cultural differences in the quantity and the types of speech that infants are exposed to and bringing those two literatures, these two robust literatures and understandings together in a way that paints a coherent picture, we’re just not there yet.