ABSTRACT
One can say, simply, that intelligence is "the ability to learn." There is no reliable way to measure intelligence—because nobody knows precisely what it is. Part of it is inherited and part results from environmental experience, part of it is general and part is specialized. The work of various psychologists, notably a group at the University of Southern California headed by J. P. Guilford, indicates that intelligence is not unitary in character. Binets material was the basis for intelligence tests developed in this country in 1916 by Lewis Terman of Stanford University; and, with periodic revisions, the Stanford-Binet tests have been the most commonly used measure of intelligence ever since. Relative newcomers, favored by many, are the Wechsler Intelligence Scale and the Wechsler Intelligence Scale for Children. There are various statistical methods employed which estimate the genetic component in general intelligence; it is believed to be approximately 70 percent.
