Proceedings of the Annual Meeting of the Cognitive Science Society

When reasoning about sequences of events, English-speaking adults often invoke a “mental timeline,” stretching from left (past) to right (future). Although the direction of the timeline varies across cultures, linear representations of time are argued to be ubiquitous and primitive. On this hypothesis, we might predict that children should spontaneously invoke a timeline when reasoning about time. However, little is known about how the mental timeline develops. Here, we use a sticker placement task to test whether 3- to 6-year-olds spontaneously produce linear, spatial representations of time. We find that, while English-speakers under age five rarely adopt such representations spontaneously, a spatial prime increases the percentage of 4-year-olds producing linear, ordered representations from 36% to 76%, indicating that by this age, children can readily align the domains of space and time. Nevertheless, these representations often do not take on the conventionalized left-to-right orientation until age 5 or 6.