Object-Oriented Play: Theoretical Underpinnings, Empirical Insights and Practical Applications in Early Childhood Education and Care

For young children, every object offers opportunities for exploration, manipulation, and discovery. Through interacting with objects and materials, children learn about their properties and affordances, developing an understanding not only of what an object is but also what it can do and what they can do with it. This behavioral phenomenon—object-oriented play (OOP)—is fundamental to how children make sense of the physical world. This dissertation contributes to research on OOP and its relevance for early childhood education and care (ECEC) practice by addressing four overarching questions: What is OOP? How does it develop? How does it relate to other developmental domains? And how can ECEC professionals support it? A layered approach connects theory, empirical evidence, and practice. Chapter 2 presents a theoretical framework synthesized from genetic epistemology, cultural-historical psychology, and evolutionary psychology. OOP is defined as play focused on exploring and physically or mentally manipulating objects. The framework describes three developmentally sequenced but overlapping phases—sensorimotor exploration, physical manipulation, and mental manipulation—which form cumulative, dynamic waves of behavior. These phases are shaped by dyadic and triadic interactions and contribute to cognitive, social, and (sensori)motor development. Chapter 3 examines relations between OOP and early motor/language development through a systematic review. Sensorimotor exploration shows consistent positive associations with fine motor and visuospatial skills, while evidence for physical manipulation is more mixed. Randomized controlled trials support overall positive effects of OOP on motor development, moderated by children’s crawling ability and initial motor level. For language, sensorimotor exploration and physical manipulation relate positively to vocalizations, gestures, and expressive and spatial vocabulary, while findings for receptive vocabulary are less consistent. Moderating factors include object type, gender, and the interplay between caregiver input and children’s attention. Chapter 4 reports a qualitative case study on how children engage with rules and repetition in OOP. Children explore, follow, and impose rules based on object properties and affordances. Four rule-related behaviors are identified: uncovering properties through sensorimotor exploration; following sensorimotor affordances to initiate actions; imposing patterns or categories based on intentional affordances; and experimenting with or comparing affordances. Repetition emerges as a central learning mechanism, ranging from simple repeated actions to increasingly structured sequences. Chapter 5 presents a large observational study examining age-related patterns in OOP among two- to four-year-olds. With age, children engage in longer, more diverse, and more complex action sequences, use more objects, and show more repetition. Mixed-model regressions reveal a linear decline in sensorimotor exploration and a linear increase in physical manipulation. Although descriptive patterns suggest growth in mental manipulation, it was difficult to observe reliably. These findings clarify the developmental phases and partially support the hypothesized overlapping OOP waves. Chapter 6 further analyzes physical manipulation, distinguishing functional behaviors (using objects according to physical or cultural function) and organizational behaviors (arranging objects by properties or function), both ranging from non-relational to increasingly complex relational actions. Chapter 7 presents an educational design research project developing the LOOP-toolkit—information cards and an action-oriented observational tool to support ECEC professionals in observing, understanding, and guiding OOP. Tested and refined in professional learning communities, the toolkit improved recognition of nuanced OOP behaviors, and professionals emphasized the need for a manual and a professional-development program. Chapter 8 synthesizes the findings: OOP is more multifaceted than previously conceptualized; it develops through overlapping phases; it supports developmental cascades; and guiding OOP requires careful observation and practical tools. Overall, this dissertation underscores the fundamental role of OOP in early development and shows that it both shapes and is shaped by motor and language growth, offering a powerful context for learning. ECEC professionals can support children by observing, interpreting, and enriching this natural form of play.