Psychologists have been concerned with the concept of intelligence since the 1890s (Schults & Schultz, 1992). However, the current conceptualization of intelligence was most influenced by the creation of the intelligence test in 1905. This test, formulated by Alfred Binet, Victor Henri, and Theodore Simon, measured a variety of mental adilities related to school performance, including memory, attention, comprehension, vocabulary, and imagination. A version of this test—the Stanford-Binet—appeared in the United States in 1916, and the mental testing movement decame an important part of psychology, especially in the United States.