Reviewed by Susan S. Scribner

One of the more frustrating arguments a child advocate can encounter, when trying to support the need for early intervention and prevention programs, is a skeptic who claims that such programs don't make a difference. How do you convince a naysayer that the continuing presence of poverty and other societal ills is actually the result of not intervening early or often enough?

Betty Hart and Todd R. Risley were disheartened when, despite their best efforts, the preschool program they developed in urban Kansas City failed to equalize the large discrepancies in language development between high- and low-income children. Rather than abandoning their program, they were determined to find out why their efforts had only limited success. With the hypothesis that parenting styles must differ widely, they set out to discover exactly which features of parent-child interaction impacted the rate of vocabulary growth.

Their ambitious research methods were truly impressive. They recruited 42 families with very young children and for almost 2 1/2 years spent one hour per month with each family in the home, recording every word spoken between parent and child. The study group consisted of 13 professional, 23 working class and 6 welfare families. At the end of this painstaking process (and they note wryly that in 3 years, neither they nor their assistants took a day of vacation), they had amassed 1,300 transcripts of approximately 20 pages each. Several more years of work were necessary to code and analyze every word.

Hart and Risley found that the widening gap between the vocabulary growth of children from professional, working class and welfare families across the first three years of the children's lives could be attributed to the overwhelming differences in the amount of verbal interaction the parents had with their children. There was a difference of almost 300 words spoken per hour between professional and welfare parents. As a result, by age 3, the professional families' children actually had a larger recorded vocabulary than the welfare families' parents.

The authors extrapolate the differences in words heard per hour to one year and arrive at the remarkable estimate that the children in professional families hear approximately 11 million words, the children in working class families 6 million words and the children in welfare families only 3 million words annually. The welfare children would require 41 hours per week of out-of-home enriched experience to make up this deficit. No wonder our meager prevention efforts are not having a lasting impact!

Hart and Risley delved deeper into the richness of the parent-child interactions. They developed a set of five quality indicators, including vocabulary, sentence structure, number of choices given to the children, responsiveness to the children's speech, and the emotional quality of the interactions. These features accounted for a significant amount of variance in the children's vocabulary growth, vocabulary use and IQ scores at age 3, and were better predictors than race, gender or birth order. These differences held up at age nine, when the children were again tested for vocabulary and language skills.

Why would parental speech have such an impact on children's development? The authors discuss some of the developmental functions of language. Vocabulary defines and labels a child's experience in terms of the family culture. Language reflects the parent's view of what the child should notice and think about the world, family and self. In addition, the affect associated with language makes human sounds distinctive and, hopefully, pleasant.

This latter point was another striking research finding. Of the three socioeconomic levels studied, only the children in welfare families heard feedback that was overwhelmingly (80 to 90%) negative. This negative tone surely affects the children's self-concept, motivation level and expectations.

The authors acknowledge that late twentieth century parenting has become a complicated task. They caution that

"There can be scant hope for better parenting in a society that assumes that nuclear families and single-parent households can turn out well-informed, highly motivated, and well-behaved children in conditions that would almost certainly lead any other enterprise into bankruptcy. Entrusting the future of the nation and the lives of its children to a work force of parents offered little training, no support and no quality control can continue only if there is no alternative" (p. 212).

But the findings are cause for action, not despair. If the quantity and quality of the words heard by a child in the critical first three years of life are so important, what intervention programs can make a difference? Hart and Risley propose supports such as quality child care, parent aides and parent mentors to increase parental skill level. They ruefully admit that in our current society with its emphasis on "rugged individualism," such reform is unlikely to happen. The authors close by urging the formation of a "special interest group" of parents who are concerned about the next generation.

Meaningful Differences is an important addition to the growing and long-overdue body of knowledge that recognizes the importance of the first three years of life. The comprehensiveness and depth of the study make the results impossible to dispute. Fortunately, the authors plan a second book that follows the children of the 42 families as they grow.

While the book is written in an academic style, it is punctuated with wry humor and reads quickly. Professionals and parents will come away with a renewed commitment to improve the lives of young American children.

Susan S. Scribner is Senior Policy Analyst for Citizens for Missouri's Children, a non-profit child advocacy organization located in St. Louis. Susan is the author of five KIDS COUNT in Missouri reports and the organization's first Children's Budget Watch report, Making Sense of the Change. She is the mother of the garrulous Abby, 6 and Daniel, 3.