g factor
The general intelligence factor (g) is a statistical construct representing shared variance across diverse cognitive tasks.
Reviewed by: Scientific Review Team · Last reviewed: July 2026
In psychometrics, g (general intelligence) is the latent trait that explains why performance on different cognitive tests tends to correlate positively. Most standardized IQ batteries aim to estimate g through multiple subtests. It is not a single brain module but a summary of broad reasoning ability.
Synonyms: general intelligence, general mental ability
Related terms
Used in
- /iq-score-chart/
- /iq-score-chart/research/
- /iq-score-chart/research/iq-scale-explained/
- /iq-score-chart/research/what-does-my-iq-score-mean/
- /official-iq-test-types/
- /official-iq-test-types/research/
- /official-iq-test-types/research/stanford-binet-test-explained/
- /official-iq-test-types/research/wais-iq-test-explained/
Related concepts
- expert · introduced
Charles Spearman - entity · measures
Wechsler Adult Intelligence Scale (WAIS) - reference · defines
General Intelligence (1904) - term · related to
Fluid intelligence - term · related to
Percentile - multimedia · featured in
Intelligence and IQ (Crash Course Psychology #23)
Related media
Intelligence and IQ (Crash Course Psychology #23)
Introductory overview of intelligence testing concepts for glossary readers.
Source: Crash Course / PBS Digital Studios
Official YouTube embed per platform terms; © rights holder.
FAQ
Is g the same as IQ?
IQ scores are practical estimates of g on a normed scale (mean 100, SD 15 on many tests). They are closely related but not identical to every narrow skill.
Can g be trained?
Short-term practice can raise specific test scores; long-term changes in g are debated. Training effects often fade or do not transfer widely.
Scientific sources
- Spearman, C. (1904). General intelligence. American Journal of Psychology.
- Carroll, J. B. (1993). Human cognitive abilities.