This study demonstrates the merits of evaluating a newly developed battery of executive function tasks, designed for use in early childhood, from the perspective of item response theory (IRT). The battery was included in the 48-month assessment of the Family Life Project, a prospective longitudinal study of 1292 children oversampled from…

Individual differences in children's performance on a classification task are modeled by a two component binomial mixture distribution. The model accounts for data well, with variance accounted for ranging from 87 to 95 percent. (RJC)

Explored genetic and environmental etiologies of individual differences in printed word recognition and related skills in identical and fraternal twin 8- to 18-year-olds. Found evidence for moderate genetic influences common between IQ, phoneme awareness, and word-reading skills and for stronger IQ-independent genetic influences that were common…

Examined whether writing and working memory (WM) were related to general or process-specific system, whether WM tasks operated independently of phonological short-term memory (STM), and whether WM predicted writing variance beyond that predicted by reading. Found a four-factor model reflecting phonological STM, verbal WM span, executive…

Examined effect of familiarization on 3.5-month-olds' retention of visual stimuli with varying delay times. Found support for retention models in which direction of attentional preferences (novel, familiar, or null) depends on memory accessibility. Short lookers showed better retention over time than long lookers, indicating that much of the…

Three studies examined the ability of 8- and 9-year-olds and young adults to use sample monotonicity and diversity information according to the similarity-coverage model of category-based induction. Found that children's difficulty with this information was independent of category level, and may be based on preferences for other strategies…

An error in the data analysis for a study reported in a 1988 paper by Kail is cited. The paper postulated a model that explained individual differences in the speed of processing on cognitive tasks. Reanalysis of the data suggested that support for the original conclusions is considerably weaker than reported. (LB)

Compared rate of conflict, conflict resolution, and the appearance of reflection on emotions and literate language in friend and nonfriend dyads of kindergarten children. Found that, although rates of conflicts were similar, friends resolved conflicts more frequently than nonfriends and generated more emotional and literate language. Support was…