Although some evidence indicates that even very young children engage in rudimentary forms of strategic behavior, the underlying mechanisms remain largely unknown. This study tested the hypothesis that uncertainty monitoring underlies such behaviors. Three-, four-, and five-year-old children ("N" = 88) completed a perceptual…

In 3 studies (N = 188) we tested the hypothesis that children use a perceptual access approach to reason about mental states before they understand beliefs. The perceptual access hypothesis predicts a U-shaped developmental pattern of performance in true belief tasks, in which 3-year-olds who reason about reality should succeed, 4- to 5-year-olds…

Toddlers show a surprising lack of knowledge about solidity when they are asked to search for a ball that rolled behind a screen and stopped at a barrier whose top was visible above the screen. They search incorrectly, failing to take into account the position of the barrier. This study examined details of this failure by simplifying the task in 2…