Jerome Bruner was an American psychologist who made significant contributions to human cognitive psychology. He introduced the theory of constructivism and discovery learning, which holds that learning involves constructing new ideas based on prior knowledge. Bruner also developed the concept of a spiral curriculum in which any subject can be taught at any age appropriately tailored to a child's cognitive abilities. His theory of instruction included activating curiosity through problem-solving, relating new knowledge simply to what is already known, using multiple modes of representation, and sequencing material in order of increasing complexity.