ABSTRACT
One of the oldest and most thoroughly studied concepts in psychology is the concept of intelligence. Yet the term “intelligence” still escapes precise definition. There are so many different kinds of behavior that are indicative of intelligence that identifying the essence of them all has seemed virtually impossible. Studies of the interrelationships among human abilities indicate that there are two basic types of intelligence: fluid intelligence and crystallized intelligence. Fluid intelligence is rather formless; it is relatively independent of education and experience; and it can “flow into” a wide variety of intellectual activities. Crystallized intelligence, on the other hand, is a precipitate out of experience. Crystallized intelligence increases with a person’s experience, and with the education that provides new methods and perspectives for dealing with that experience. These two major kinds of intelligence are composed of more elementary abilities, called “primary” mental abilities.
