Social learning promotes understanding of the physical world: Preschool children’s imitation of weight sorting

• Through imitation, 4-year-olds learned to categorize visually-identical objects by weight.
• Children learned from demonstrations that featured intentional sorting.
• Categorization by weight was found at age 48 months, but not 36 months.
• Children’s imitation may be gated by their cognitive development.
• Imitation goes beyond reproducing surface behavior, and includes abstract rules.

We investigated whether social learning, specifically imitation, can advance preschoolers’ understanding of weight. Preschoolers were randomly assigned to experimental and control groups. The experimental group saw an adult intentionally categorize an array of four visually identical objects based on weight. Then, children’s weight-based sorting of the objects was evaluated. To test generalization, children were presented with novel objects (differing in shape, color, and weight from the original ones) and not shown what to do with them. Results indicate that 48-month-olds learned to sort by weight via observing the adult’s demonstration of categorization and that children generalized weight sorting to novel objects. This shows that children imitate at a more abstract level than merely motor actions. They learn and imitate generalizable rules. 36-month-olds did not succeed on this weight sorting task. Children’s cognitive development constrains what children learn through social observation and imitation.