Influential Theorists & Researchers
This scientist (author of The Descent of Man) defined intelligence as the adaptive behaviors in animals and humans.
Charles Darwin
This practice is the forced sterilization of individuals based on the results of IQ tests and disability status
These scores have a mean of 100 and a standard deviation of 15
Standard Scores
"Intelligence is the aggregate or global capacity of the individual to act purposefully, to think rationally and to deal effectively with his environment. It is global because it characterizes the individual's behavior as a whole; it is an aggregate because it is composed of elements or abilities which, though not entirely independent, are qualitatively differentiable. By measurement of these abilities, we ultimately evaluate intelligence. But intelligence is not identical with the mere sum of these abilities, however inclusive."
David Wechsler's definition of intelligence (1939)
This hierarchical model of intelligence recognizes a general factor (g) in the highest stratum; fluid intelligence (Gf), crystallized intelligence (Gc), general memory and learning (Gsm), broad visual perception (Gv), broad auditory perception (Ga), broad retrieval ability (Gr), and broad cognitive speediness (Gs) in the second stratum; and very narrow and specific factors in the lowest stratum.
Cattell-Horn-Carroll (CHC) Framework of Intelligence
This theorist and noted eugenicist said: "It is to obtain a general knowledge of the capacities of a man by sinking shafts, as it were, at a few critical points. In order to ascertain the best points for the purpose, the sets of measures should be compared with an independent estimate of the man's powers. We thus may learn which of the measures are the most instructive."
Francis Galton
The basic tenets of this 'science' were that the brain was the organ of the mind, the mind could be reduced to a number of faculties, the faculties were located in distinct organs of the brain, and that the surface of the skull was determined by the external form of the brain.
Phrenology
Processes that are not directly measurable, but which are inferred to have real existence and to give rise to measurable phenomena
Hypothetical Constructs
Intelligence is the "continuous adjustment" of "inner to outer relations"
Herbert Spencer's definition of intelligence (1855)
Carroll (1993) cautioned that his research "paid very little attention to the importance, validity, or ultimate usefulness of the ability factors that have been identified."
Cautions with overinterpretation of narrow factors
Discovered a general intellectual factor
Charles Spearman
This theory, which contrasted with Spearman's g, proposed the existence of 8 primary abilities based on factor analytic studies: Verbal Comprehension (V), Word Fluency (W), Number Facility (N), Memory (M), Visualizing or Space Thinking (S), Perceptual Speed (P), Induction (I), and Speed of Judgement (J).
Thurstone's Primary Mental Abilities
Originally calculated by dividing mental age by chronological age and multiplying the product by 100
IQ
"Intelligence is the general capacity of an individual consciously to adjust his thinking to new requirements: it is general mental adaptability to new problems and conditions of life"
William Stern's definition of intelligence (1914)
This neuropsychological theory is based on processes rather than abilities. It is the foundation of the Planning, Attention, Simultaneous, and Successive (PASS) Theory of Intelligence
Luria's Neuropsychological Model of Mental Processing
Generally acknowledged as the "father of intelligence tests," this self-taught psychologist developed an intelligence scale to assist the French government's exploration of how to differentiate education for children with disabilities.
Alfred Binet
This theory proposed that intelligence is comprised of two general factors: Fluid (Gf) and Crystallized (Gc) intelligence. Fluid intelligence was defined as a facility in reasoning, particularly where adaptation to new situations is required. Crystallized intelligence referred to accessible stores of knowledge and the ability to acquire further knowledge via familiar learning strategies.
This statistical procedure allows for the exploration and extraction of latent factors or variables that are measured by a particular instrument. Pioneered by Thurstone.
Factor Analysis
"Intelligence ... is the capacity to acquire capacity"
Herbert Woodrow's definition of intelligence (1921)
Based on decades of research, which score yielded by measures of developed cognitive ability has the most explanatory power?
Overall intelligence test score (e.g., FSIQ etc.)
He adapted the Binet-Simon Intelligence Scale (later called the Stanford-Binet) and was a member of the National Research Council that created the Army Mental Tests.
Lewis Terman
The addition of new ability factors such as visual reasoning, retrieval, memory, auditory processing, kinesthetic awareness, and cognitive speed comprised this expanded theory.
Cattell and Horn's Extended Gf-Gc Theory
Refers to the degree to which evidence and theory support the interpretations of test scores for proposed uses of tests.
Validity
"Intelligence is mental self-government.... The essence of intelligence is that is provides a means to govern ourselves so that our thoughts and actions are organized, coherent, and responsive to both our internally driven needs and to the needs of the environment"
Robert Sternberg's definition of intelligence (1986)
It is vital to interpret cognitive scores based on....
The theoretical framework with which the test was developed