There’s significant research emerging that demonstrates just how important the earliest months of life are to the development of intellectual capacity. As recounted in our book Disrupting Class, two researchers, Todd Risley and Betty Hart, studied the effects of how parents talk to a child during the first two and a half years of life. After meticulously observing and recording all of the interactions between parent and child, they noticed that on average, parents speak 1,500 words per hour to their infant children. “Talkative” (often college-educated) parents spoke 2,100 words to their child, on average. By contrast, parents from less verbal (and often less-educated) backgrounds spoke only 600 per hour, on average. If you add that up over the first thirty months, the child of “talkative” parents heard an estimated 48 million words spoken, compared to the disadvantaged child, who heard only 13 million. The most important time for the children to hear the words, the research suggests, is the first year of life.
Risley and Hart’s research followed the children they studied as they progressed through school. The number of words spoken to a child had a strong correlation between the number of words that they heard in their first thirty months and their performance on vocabulary and reading comprehension tests as they got older.