Spatial preposition use predicts children’s spatial map formation

Children’s ability to build a precise map-based representation of their physical environment increases with age and experience. A key contributor to age-related improvements in spatial map formation is the ability to integrate multiple landmarks within an environment into a single representation. Whilst the ability to form integrated maps of space follows a protracted developmental trajectory, children can communicate and reason about spatial objects and relations from a young age. Here, we tested whether children’s verbal expression of prepositions, a form of relational language that links elements of spoken (or written) language together, predicted children’s ability to form relationships between entities in space. We hypothesized that relational abilities across cognitive domains should track one another, reflecting the development of more complex forms of knowledge that consider multiple entities simultaneously. Across two studies, we assessed children’s (6-12 years) and adults’ (N = 171) preposition use and spatial memory. A map-reading task required participants to give verbal directions for two routes on a map. A virtual navigation task required participants to learn and remember object locations in a virtual arena. A spatial memory composite score captured performance, incorporating metrics of path efficiency, distance error, and angular error. Linear mixed effects models consistently showed that greater preposition use during map-reading was predictive of spatial memory performance in children but not adults. These replicable data show that children’s use of relational language, which can be used to link spatial landmarks and locations, parallels their ability to form a more accurate representation of space.