Toward a Causal Science of Early Play?

Young children across the globe devote much of their early years to physically engaging with the world-stacking, climbing, scribbling, and tinkering with objects. Although this embodied play is widely believed to fuel key cognitive processes like attention, memory, and executive function, most supporting evidence remains descriptive or correlational. Here, we review findings from embodied cognition research and highlight why direct experimental manipulations-rather than observations alone-are critical to demonstrating whether and how infants' and children's sensorimotor engagements shape their cognitive trajectories. We discuss emerging technologies (e.g., motion capture, wearable eye-tracking) that can assess play in natural contexts, along with the use of embodied computational models for testing the impact of altered object affordances and caregiver scaffolding. We propose designs for real-world interventions such as rotating different types of toys, systematically modifying motor demands, and tracking outcomes in attention and problem-solving, which can bring new causal clarity to developmental science. We argue that a causal science of play will have broad implications for early education, policy, and intervention programs that aim to transform the theory of embodied cognition into practical benefits for children's learning and development.