The use of geometric properties of 2D arrays across development

Four- to 10-year-old children (n = 50) participated in a 2D search task that included geometry (with- and without lines) and feature conditions. During each of 27 trials, participants watched as a cartoon character hid behind one of three landmarks arranged in a triangle on a computer screen. During feature condition trials, participants could use the unique features of landmarks to locate the hidden character. During geometry condition trials the landmarks were identical, and participants had to rely on the geometric properties of the triangle they formed to locate the hidden character. In the feature condition, search accuracy was high for children of all ages. In the geometry condition (both with- and without lines), there was a sharp developmental trend in which 4-year-olds showed poor search accuracy, but performance improved with age and was at ceiling by 9- to 10-years. The presence of lines connecting the landmarks boosted performance most dramatically for the youngest children. Findings are discussed in the context of the broader literature on spatial cognition in human and non-human animals.