English-speaking adults recruit a left-to-right “mentaltimeline” (MTL) when thinking about time. The origins of theMTL are debated, with some arguing that it is a culturalconstruct and others arguing that it is rooted in innateassociations between time and space. Here we ask whetherpreschoolers, with limited experience with cultural practicesthought to shape the MTL, prefer conventional linearrepresentations of temporal events. English-speakingpreschoolers and adults were told stories and asked to choosewhich of two visual representations best illustrated the story.As expected, adults overwhelmingly preferred images thatwere linearly ordered from left-to-right. Five-year-olds alsopreferred left-to-right to right-to-left series, but were equallylikely choose left-to-right and top-to-bottom. By contrast,3-year-olds chose at random, apparently insensitive to thespatial ordering of event-denoting images. These resultssuggest that attention to the ordinal structure of visualrepresentations of time increases across early childhood, andthat adults’ preference for horizontal space-time mappingsresults from increased cultural conditioning.