SCORES ON THE MACARTHUR COMMUNICATIVE DEVELOPMENT INVENTORY OF CHILDREN FROM LOW-INCOME AND MIDDLE-INCOME FAMILIES

This study compared the language skills in a group of very low-income toddlers with those of a middle-income sample matched on age and sex. The assessment instrument was the MacArthur Communicative Development Inventory (CDI) for toddlers, a parent report form. The scores for the low-income group were strikingly lower on the three key indices evalu ated: size of expressive vocabulary, age of appearance of word combina tions, and complexity of utterances. The entire low-income distributio n was shifted about 30% toward the lower end of the middle-income dist ribution for both productive vocabulary and grammatical development. T he magnitude of these income/social class effects was larger than repo rted in most prior reports for children in this age range. This findin g underscores the cautionary note issued by the CDI developers, which states that the published CDI norms, based on a middle-class sample, m ay not be directly applicable to low-income samples.