The 30 Million–Word Gap Relevance for Pediatrics

Abstract

As many as 40% to 50% of the children pediatric clinicians serve are growing up in low-income households. Among the myriad physical and mental health sequelae of early adversity and toxic stress, language development appears to be one area particularly vulnerable to the stressors associated with poverty. The effects of poverty on language development have been documented in children as young as 9 months, becoming more clinically evident by 24 months.1 The consequences of early adversity–related language delays may be profound, leading to later learning delays, school failure, and lifelong social and economic consequences.2

This income-related gap in children’s language development has been linked in numerous studies to the quantity and quality of language input children receive from their parents, family members, and caregivers. Hart and Risley3 carried out the landmark study documenting this influence of children’s early environments on their later vocabulary growth. They observed that young children from low-income families heard approximately 600 words per hour compared with 2100 words per hour for children from high-income families. Extrapolating from this hourly discrepancy data, they estimated that by the time children reached age 4 years, those from higher-income families were likely to have heard roughly 30 million more words than low-income children. In addition, lower-income parents have been observed to use fewer complex sentences and rare vocabulary words, ask fewer questions of children, and use more prohibitives and directives—language that tells children what to do and not do—rather than pose comments that might elicit conversation. This qualitative and quantitative difference in language exposure, the “word gap,” is significant in that it often leads to later disparities in children’s academic achievement via effects not only on language development2 but also on cognitive processing1 and building self-regulation skills.4

Numerous community-based interventions have been shown to be effective in improving children’s language learning environments and outcomes.5 Some of the largest-scale endeavors include Providence Talks (a program in which low-income families with young children in Providence, Rhode Island, are given audio-recording technology that provides feedback about how many words their children hear every day), Georgia’s Talk to Me Baby program, and the Talking Is Teaching initiative of Too Small to Fail.

However, some recent commentators have criticized the emphasis placed on word gap initiatives, with opposition to the “simplistic” approach of focusing on number of words spoken as a solution to poverty’s health effects as well as concern for implicit bias in the way researchers describe low-income and minority parenting.6 We argue that emphasis on the word gap in pediatric practice is not only appropriate but also a valuable tool for partnering with families and teaching trainees.