Children’s Spontaneous Science, Technology, Engineering, and Mathematics (STEM) Behaviours and Engagement in Play with Loose Parts

Abstract Children incorporate what they find in their environment into their play, transforming everyday objects and materials into creativity and exploration. Termed loose parts, these versatile, natural or manufactured materials (e.g., cardboard, pipes, buttons, beads) are widely recommended for supporting young children’s early STEM engagement. While engaging, there is limited empirical work documenting young children’s indoor STEM behaviours through direct observation. Foundational research is needed to delineate how children’s cognitive capacities, home learning environment, and STEM engagement interact during early play to inform more targeted and developmentally grounded STEM education in early years. Using a within-subjects experimental design, we examined children’s STEM behaviours and engagement (N = 60, 32 girls, M = 58.6 months, SD = 10.9) during unstructured solitary play with loose parts and with toys with limited function and affordance (i.e., toy percussion instruments, control). Children’s cognitive functioning, executive function, and home learning environment were assessed via standardized measures and parent reports. Children demonstrated significantly more STEM behaviours with loose parts, particularly constructing, exploring mathematical concepts, communicating intentions, and reasoning about how things work. These behaviours did not differ by sex. Linear regression analyses showed that cognitive functioning predicted STEM engagement with loose parts, while verbal comprehension was the strongest predictor in the control condition. Construction behaviours were the most common STEM behaviours. Parents’ attitudes toward play and children’s executive functioning predicted construction behaviours. Findings underscore the importance of aligning play-based learning environments with children’s cognitive profiles and home experiences, rather than assuming uniform benefits from loose parts across all children.