Children who live in homes with more wealth talk differently and more with their parents than children who grow up with less money. Todd Hart and Betty Risley compared middle-class families to families living at or below the poverty line by tape-recording the interactions of forty-two families from the time the children were nine months old until they were three years old. Children whose parents were well educated and held professional-level jobs heard about 2,100 words per hour. Welfare children heard about 600 words an hour. By the time the subjects in the study were four years old, the middle-class children of professional families heard as many as 48 million words. In contrast, children in families on welfare heard as few as 13 million words.
The difference in language environment goes beyond sheer numbers. Children from families with more money heard a different kind of talk from that heard by children with less money. Parents from the wealthier families were more likely to talk about the world around them, to identify what was interesting, and to discuss what was worth noticing and worth remembering. Some parents seemed to provide their children with a running narration of experience and also encouraged their children to narrate experience. This measure, which Hart and Risley called "extra talk (non-business talk)," taken when children were three years old, had a 77-percent correlation with the Peabody Picture Vocabulary test at third grade. In other words, families that engaged in a lot of "extra talk" had children who were much more likely to succeed in school.
It is not clear why families with greater wealth do this more than families without money. It might be because families with more money tend to have gone to better schools and to have spent more time in school. Or it might be that families with more money are more likely to have jobs that involve a higher level of education and require more conversation, more exchange of information, and possibly more time in deliberation.