Fluid and crystallized intelligence

In psychology, fluid and crystallized intelligence (respectively abbreviated Gf and Gc) are factors of general intelligence, identified in 1971 by Raymond Cattell. Concepts of fluid and crystallized intelligence were further developed by Cattell's student John L. Horn. In psychology, fluid and crystallized intelligence (respectively abbreviated Gf and Gc) are factors of general intelligence, identified in 1971 by Raymond Cattell. Concepts of fluid and crystallized intelligence were further developed by Cattell's student John L. Horn. Fluid intelligence or fluid reasoning is the capacity to reason and solve novel problems, independent of any knowledge from the past. It is the ability to analyze novel problems, identify patterns and relationships that underpin these problems and the extrapolation of these using logic. It is necessary for all logical problem solving. Fluid reasoning includes inductive reasoning and deductive reasoning. Crystallized intelligence is the ability to use skills, knowledge, and experience. It does not equate to memory, but it does rely on accessing information from long-term memory. Crystallized intelligence is one's lifetime of intellectual achievement, as demonstrated largely through one's vocabulary and general knowledge. This improves somewhat with age, as experiences tend to expand one's knowledge. Crystallized intelligence is indicated by a person's depth and breadth of general knowledge, vocabulary, and the ability to reason using words and numbers. It is the product of educational and cultural experience in interaction with fluid intelligence. Crystallized and fluid intelligence are believed to be separate neural and mental systems. Fluid and crystallized intelligence are thus correlated with each other, and most IQ tests attempt to measure both varieties. For example, the Wechsler Adult Intelligence Scale (WAIS) measures fluid intelligence on the performance scale and crystallized intelligence on the verbal scale. The overall IQ score is based on a combination of these two scales. Fluid and crystallized intelligence were originally identified by Raymond Cattell. Concepts of fluid and crystallized intelligence were further developed by Cattell's student, John L. Horn. Since Cattell's and Horn's publications, the concepts of fluid and crystallized intelligence have become so ingrained in the field of intelligence that they are no longer routinely attributed to Cattell or Horn—much as Cattell's scree plot became ingrained in the practice of factor analysis or Freud's concept of the subconscious is ingrained in psychology and in the public's perceptions of the mind. Fluid and crystallized intelligence are discrete factors of general intelligence, or g. Although formally recognized by Cattell, the distinction was foreshadowed by Charles Spearman who originally developed the theory of g and made a similar observation regarding the difference between eductive and reproductive mental ability. According to Cattell, '...it is apparent that one of these powers… has the 'fluid' quality of being directable to almost any problem. By contrast, the other is invested in particular areas of crystallized skills which can be upset individually without affecting the others.' Thus, his claim was that each type, or factor, was independent of the other, though many authors have noted an apparent interdependence of the two. Fluid intelligence includes such abilities as pattern recognition, abstract reasoning, and problem-solving. Evidence is consistent with the view that Gf is more affected by brain injury. Impaired performance on some tasks measuring fluid intelligence and enhanced performance on others are found on some measures in individuals with autism spectrum disorders including Asperger syndrome.