Originating in the United States in the late 1970s, instructional theory is influenced by three basic theories in educational thought: behaviorism, the theory that helps us understand how people conform to predetermined standards; cognitivism, the theory that learning occurs through mental associations; and constructivism, the theory explores the value of human activity as a critical function of gaining knowledge.[4] Instructional theory is heavily influenced by the 1956 work of Benjamin Bloom, a University of Chicago professor, and the results of his Taxonomy of Education Objectives—one of the first modern codifications of the learning process. One of the first instructional theorists was Robert M. Gagne, who in 1965 published Conditions of Learning for the Florida State University's Department of Educational Research.