Proceedings of the Annual Meeting of the Cognitive Science Society

Toddlers can learn cause-effect relationships between single actions and outcomes. However, real-world causality is often more complex. We investigated whether toddlers (12- to 35-month-olds) can learn that a sequence of two actions is causally necessary, from observing the actions of an adult demonstrator. In Experiment 1, toddlers saw evidence that performing a two-action sequence (AB) on a puzzle-box was necessary to produce a sticker, and evidence that B alone was not sufficient. Toddlers were then given the opportunity to interact with the box and retrieve up to five stickers. Toddlers had difficulty reproducing the required two-action sequence, with the ability to do so improving with age. In Experiment 2, toddlers saw evidence that performing a single action (B) was sufficient to produce an effect (i.e., a sequence was not causally necessary). Toddlers were more successful and performed fewer sequences in Experiment 2, suggesting some sensitivity to the sequential causal structure.