<![CDATA[Despite expanding global interest in early childhood Science, Technology, Engineering, and Mathematics (STEM) education, empirical evidence regarding pedagogical integration, teacher belief systems, and early cognitive outcomes remains conceptually fragmented and geographically asymmetric. To address this gap, this systematic literature review applies PRISMA 2020 guidelines and the SPIDER eligibility framework to synthesize a primary empirical corpus of N = 20 studies within a broader 30-source academic foundation. Grounded in Vygotsky’s sociocultural theory and Papert’s constructionism, this review evaluates early childhood STEM instructional mechanics including Engineering Design Process (EDP) cycles, screen-free tangible robotics, digital manipulatives, and arts-integrated storybooks for learners aged 3 to 8 years. Synthesized findings reveal a clear developmental continuum: toddler learning (ages 3-4) relies primarily on open-ended sensory discovery, whereas kindergarten settings (ages 5-6) require structured teacher scaffolding to guide children from initial prototyping toward systematic testing, spatial reasoning, and failure optimization. Furthermore, teacher pedagogical belief structures significantly moderate curriculum execution; educators holding discrete beliefs regarding play and academics achieve higher technical coding gains through structured modules, whereas those with integrated beliefs prioritize open-ended exploration without diminishing computational thinking or debugging skills. Methodological quality appraisal via the Mixed Methods Appraisal Tool (MMAT 2018) confirms high overall rigor (M = 84.5%), though geographic distributions reveal severe imbalances favoring Asian and European research hubs over African and South American contexts. Ultimately, this review offers actionable theoretical, policy, and practical frameworks for curriculum designers and teacher education programs seeking to establish equitable, developmentally aligned early STEM learning environments.]]>
