PREDICTING GLOBAL MEASURES OF DEVELOPMENT AT 18-MONTHS OF AGE FROM SPECIFIC MEASURES OF COGNITIVE ABILITY AT 10-MONTHS OF AGE

Abstract

Composite scores from standardized tests taken in infancy have been shown to offer modest prediction to cognitive skills in later childhood. One possible reason for this is that early manifestations of mental development in infancy are not the basis for cognition later in childhood. One alternative hypothesis, however, is that the aggregation of composite scores on infant standardized tests obscures the measurement of specific skills that would be more predictive of meaningful outcomes. In this study, we sought to determine if (a) it was possible to extract measurement of specific skills from a standardized infant assessment, and (b) whether the indicators of those skills might relate to performance on specific tasks administered in the laboratory. To accomplish this, we derived factors from an item-level analysis of an 18-month sample of subjects' MDI responses on the Bayley Scales of Infant Development, 2nd Edition (BSID-II) and tested to determine whether these specific factors predict to, or are predicted by, specific cognitive measures given to the same sample subjects at 10-months of age. In addition, we sought to determine whether the use of factor scores as dependent variables would demonstrate better predictability than the MDI Standard Score of the BSID-II as a dependent variable. Three significant factors were derived from the 18-month-old subjects' responses to the MDI of the BSID-II: Based on item content, we named these Expressive Language, Receptive Language, and Object Manipulation. Factor scores were then calculated for each subject and entered into a multiple regression model to examine how the scores of the specific measures of cognitive abilities improved predictive ability to factors derived from the standardized development test. Scores from specific measures of problem-solving and explicit memory given to 10-month-old infants were utilized to examine possible predictability to a standardized developmental test, the BSID-II, given to the same sample (n=109) of infants at 18-months of age. Predictability of a specific measure of development to a global measure of development was promising in some instances, and the use of factor scores did improve the predictability for some outcomes. Implications of these particular analyses, including specific differences between these subscales and other's subscales that have been attempted previously are discussed. We also compared the factors to the word count and sentence length portions of the McArthur-Bates Communicative Development Inventory (MBCDI), which yielded promising correlations.