Carroll's three-stratum theory

Carroll's three-stratum theory of intelligence suggests that general intelligence, or "g," influences a range of cognitive abilities. It consists of three layers: the top (first stratum) is the general intelligence factor; the middle (second stratum) includes broad abilities like verbal and mathematical skills; and the bottom (third stratum) encompasses specific skills, such as reading comprehension or problem-solving in math. This model illustrates how general intelligence underpins various abilities and how they can be categorized into broader and more specialized skills. It emphasizes both the overarching influence of "g" and the diversity of specific cognitive talents.