To Touch or Not to Touch: The Role of Vocabulary and Object Exploration in Children's Attention to Shape

Children's ability to identify relevant object features, such as shape, plays a key role in learning object names. However, successful attention to shape (shape bias) is dependent on other factors, including children's vocabulary size as well as opportunities for object exploration. The current study explored the combined impact of both vocabulary and object exploration on attention to shape and their cascading impact on retention of object labels. Here, 336 17-to-30-month-old children completed a Novel Noun Generalization (NNG) task and were tested on retention of exemplar name-object pairings. Children in a pre-familiarization condition physically explored objects before every trial; children in a no-familiarization condition did not. Vocabulary (via MacArthur-Bates Communicative Development Inventory) significantly predicted attention to shape, and higher rates of shape-match exploration yielded a stronger shape bias. However, object exploration did not impact NNG performance or retention, and children struggled to retain word-referent mappings. Though attention to shape is thought to support learning, exploratory analyses revealed that children's NNG performance did not predict retention. The results suggest that vocabulary significantly influences word learning processes but object exploration may not offer support. Future research should consider how task demands and other cognitive abilities impact word learning.