A 7-month longitudinal study of 20 2- and 3-year-old children shows that children at an early age already know that counting words each refer to a distinct numerosity, although they do not know to which numerosity. It takes children a long time to learn the latter. (SLD)

Background: The relationship between the age of reaching infant developmental milestones and later intellectual function within the normal population remains unresolved. We hypothesised that the age of learning to stand in infancy would be associated with adult executive function and that the association would be apparent throughout the range of…

The range of meanings of "big" and "little" that mothers and their three children under age two expressed in relatively natural communication situations was studied. Longitudinal data from transcripts of conversations of middle-class mothers and their children were analyzed along with diary records kept by parents of their children's use of size…

Used observations and home visits to examine sex differences in language ability of 54 disadvantaged children at risk for poor language outcomes. Found that language difficulties increased over time, boys were at a constant disadvantage to girls in language development, and sex difference in language ability appeared even when families had similar…