The Conversational Language Profile of Children in Low Socioeconomic Environments: A Systematic Review

Purpose: Children from low socioeconomic environments (SEEs; i.e., families with parental education of high school or less and/or household income at or below federal poverty threshold) reportedly produce fewer vocabulary words compared to their higher SEE peers. However, whether that indicates a language delay or disorder is unclear since vocabulary represents only one dimension of language. We conducted a systematic review to investigate the conversational language profile of children in low SEEs and how results may vary by dimensions of language (i.e., vocabulary, grammar) and SEE (e.g., maternal education, income). Method: A systematic review following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses was completed. A literature search was conducted across three electronic databases (PsycINFO, Education Resources Information Center, and PubMed) to find studies published between 1990 and 2023 that examined the relation between children's vocabulary and grammar with their SEE using language sample analyses. Results: Twenty-two studies were reviewed. Participant demographic information, conversational language outcomes (vocabulary and grammar), and SEE indicators were summarized. Overall, studies using a between-groups research design based on SEE reported fewer significant effects than were studies examining within-sample SEE effects. In addition, associations between SEE and conversational language were mixed; however, SEE is less likely to correlate with basic grammar skills (e.g., tense and agreement) as compared to lexical diversity, mean length of utterance, and complex syntax. Finally, researchers measured SEE heterogeneously, which interfered with cross-study comparisons. Conclusions: This review describes the conversational language profile of children from low SEE, providing a potential framework for differential diagnosis to avoid overidentification. Furthermore, we suggest the conversational language profile may reflect a language difference rather than a language disorder. Clinical and social justice implications include avoiding deficit-based framing of language in low SEE contexts and using culturally and linguistically responsive assessment practices to disentangle language differences from disorders.