Psychometric tests can also be used to measure some closely related intelligence construct, in addition to intelligence itself. Examples include the United States SAT, GRE, and SSAT (Paul, 48). Apart from the Psychometric Approach, the Developmental and Information Processing Approach are used to study intelligence. The developmental approach involves examining the way children learn, whereas the information processing approach involves examining the types of skills people use to solve problems in their daily life (Earl, 67 – 71).
There are several theories of intelligence. The most noteworthy include Spearman’s two-factor theory which measures the g and s factors, Thurstone’s Primary Mental Abilities theory which measures seven factors including reasoning, arithmetic, and verbal comprehension, and the Cattell-Horn-Carroll theory, which measures a hierarchy of factors with g at the top followed by ten broad abilities, which are subdivided into numerous narrow abilities. Crystallized intelligence, quantitative reasoning, and processing speed are three of the ten broad abilities. The triarchic theory of intelligence asserts that intelligence comprises of three fundamental concepts: analytical intelligence, creative intelligence, and practical intelligence (Osho, 156). There are many more theories of intelligence, but no single approach or theory is accurate or reliable on its own.