Differences in the memory-based searching of delayed and normally developing young children

The memory-based searching of developmentally delayed and normal 2-year-old children was compared. The results of the study confirmed the hypothesis that individual differences would be minimal in a relatively noneffortful memory task, but that substantial individual differences would occur when more cognitive effort was required. The performance of the delayed and normal children was very good and quite similar in the basic memory task, which simply involved remembering the location of a toy hidden in a distinctive, natural location in a room. Substantial individual differences were found, however, in the children's ability to draw inferences about plausible locations for a missing toy based on their memory for where it had been hidden. When they discovered that their toy was not where they remembered it had been hidden (it had been surreptitiously moved by the experimenter), a group of normal children searched for the toy in places that were nearby or otherwise related to the original location of the toy. They used their memory for where the toy had been hidden to generate plausible alternative locations to search. In contrast, delayed children, who discovered their toy to be unaccountably missing from a location, persevered in repeatedly searching that same place. Unlike the normal children, they did not try something new. An important aspect of the data reported is that they reveal an important difference-not just a delay-in the cognitive functioning of young delayed children.