We discuss the limitations of hypothesis testing using (quasi-) experiments in the study of cognitive development and suggest latent variable modeling as a viable alternative to experimentation. Latent variable models allow testing a theory as a whole, incorporating individual differences with respect to developmental processes or abilities in the…

Three experiments investigated 5- through 8-month-olds' ability to encode self-propelled and caused motion and examined whether processing of motion onset changes when crawling begins. Infants were habituated (Experiments 1 and 2) or familiarized (Experiment 3) with simple causal and noncausal launching events. They then viewed the caused-to-move…

There is evidence for developmental hierarchies in the type of information to which infants attend when reasoning about objects. Investigators have questioned the origin of these hierarchies and how infants come to identify new sources of information when reasoning about objects. The goal of the present experiments was to shed light on this debate…

To find out if children could make functions before age 4, 73 children aged 1 to 4 were encouraged to imitate the use of a lever to make a beanbag fly up. Functions are mental relationships that preoperational children can make between 2 things at a time in a unidirectional way (Piaget, Grize, Szeminska, & Bang, 1968/1977). The child's…

Switching between tasks produces decreases in performance as compared to repeating the same task. Asymmetrical switch costs occur when switching between two tasks of unequal difficulty. This asymmetry occurs because the cost is greater when switching to the less difficult task than when switching to the more difficult task. Various theories about…

Two experiments yield data suggesting that the structure of children's concept of artifact function changes profoundly between age 5 and 7, with striking effects on problem-solving performance. This effect is not caused by differences in children's knowledge about the typical use of particular tools, but rather, is mediated by the structure of the…

A general theory of how children learn conservation concepts is presented. The acquisition process is described at an abstract level in terms of a rule-sampling system, implying a three-state Markov model with identifiable parameters. Three experiments testing the model's quantitative predictions about conservation learning experiments are…