The poorer parents are, the less they talk with their children.
In the nineteen-eighties, two child psychologists at the University of Kansas, Betty Hart and Todd Risley, began comparing, in detail, how parents of different social classes talked with their children.
.. But the researchers also found that the wealthier parents consistently talked more with their kids. Among the professional families, the average number of words that children heard in an hour was twenty-one hundred and fifty; among the working-class families, it was twelve hundred and fifty; among the welfare families, it was six hundred and twenty. Over time, these daily differences had major consequences, Hart and Risley concluded: “With few exceptions, the more parents talked to their children, the faster the children’s vocabularies were growing and the higher the children’s I.Q. test scores at age 3 and later.”