The chapter introduces the psychological theory of constructivism, which is a current and influential approach to learning and development. Initially based on the work of Jean Piaget and Lev Vygotsky, constructivism has been extended by contemporary biologists and cognitive scientists to explore complexity and emergence. This theory challenges traditional behaviorism and maturationism, emphasizing cognitive development and deep understanding over linear learning processes. Behaviorism, which views learning as a system of behavioral responses to physical stimuli, is contrasted with constructivism, which focuses on active learner reorganization and the construction of new perspectives. Maturationism, which posits that conceptual knowledge is dependent on the developmental stage of the learner, is also discussed, highlighting the importance of age norms and developmental milestones. Constructivism, rooted in cognitive science, emphasizes the role of environmental equivalence and biological equilibration. It suggests that learning is a complex, nonlinear process driven by the interplay between the learner and their environment. The chapter delves into the concept of equilibration, a dynamic process where learners balance assimilation (organizing experience) and accommodation (adjusting to new information). This process is illustrated through examples such as Piaget's studies on snail behavior and the development of cognitive structures. The chapter also explores the work of Vygotsky, who focused on the role of social interaction, language, and culture in learning. Vygotsky introduced the concept of the zone of proximal development, where learners' spontaneous concepts meet the systematicity and logic of adult reasoning. He also discussed the role of inner speech and the dialectical tension between spontaneous and scientific concepts. Finally, the chapter addresses the debate around scaffolding, a teaching strategy that involves providing support to help learners progress beyond their current level of understanding. The effectiveness of scaffolding is debated, with some educators emphasizing modeling and direct instruction, while others focus on the constructive nature of learning and the role of new possibilities for consideration.The chapter introduces the psychological theory of constructivism, which is a current and influential approach to learning and development. Initially based on the work of Jean Piaget and Lev Vygotsky, constructivism has been extended by contemporary biologists and cognitive scientists to explore complexity and emergence. This theory challenges traditional behaviorism and maturationism, emphasizing cognitive development and deep understanding over linear learning processes. Behaviorism, which views learning as a system of behavioral responses to physical stimuli, is contrasted with constructivism, which focuses on active learner reorganization and the construction of new perspectives. Maturationism, which posits that conceptual knowledge is dependent on the developmental stage of the learner, is also discussed, highlighting the importance of age norms and developmental milestones. Constructivism, rooted in cognitive science, emphasizes the role of environmental equivalence and biological equilibration. It suggests that learning is a complex, nonlinear process driven by the interplay between the learner and their environment. The chapter delves into the concept of equilibration, a dynamic process where learners balance assimilation (organizing experience) and accommodation (adjusting to new information). This process is illustrated through examples such as Piaget's studies on snail behavior and the development of cognitive structures. The chapter also explores the work of Vygotsky, who focused on the role of social interaction, language, and culture in learning. Vygotsky introduced the concept of the zone of proximal development, where learners' spontaneous concepts meet the systematicity and logic of adult reasoning. He also discussed the role of inner speech and the dialectical tension between spontaneous and scientific concepts. Finally, the chapter addresses the debate around scaffolding, a teaching strategy that involves providing support to help learners progress beyond their current level of understanding. The effectiveness of scaffolding is debated, with some educators emphasizing modeling and direct instruction, while others focus on the constructive nature of learning and the role of new possibilities for consideration.