Is scaling up harder than scaling down? How children and adults visually scale distance from memory

In three experiments (N = 288), we examined how the direction of the scale translation impacts how 4- to 5-year-old children and adults visually scale distance from memory. Participants first watched an experimenter place an object on a learning mat and then attempted to place a replica object on a test mat that was either identical (no scaling task) or different in scale (scaling task). In Experiment 1, both children and adults had difficulty scaling up from 16 to 128 in. (1:8 scaling ratio) but not scaling down from 128 to 16 in. (8:1 scaling ratio), suggesting that scaling up was harder than scaling down. In Experiment 2, we reduced the scaling ratio from 1:8 to 1:2 and found that children and adults had no difficulty scaling up from 16 to 32 in. or scaling down from 32 to 16 in.. In Experiment 3, we kept the scale ratio the same (1:2) but increased the size of the test mat and found that participants had difficulty with both scaling up from 32 to 64 in. and scaling down from 128 to 64 in.. We conclude that scaling up is not harder than scaling down. Rather, visually scaling distance is more difficult when participants cannot view both edges of the test mat simultaneously while making the scale translation. Across all experiments, 4- to 5-year-olds were less accurate than adults in their placements overall, but they exhibited the same patterns of performance on the scaling and no scaling tasks, suggesting that visual scaling processes are age-independent. The General Discussion focuses on how visual scaling emerges from a complex interplay of cognitive processes and visual constraints.