Psychometric Theories of Intelligence

PsychologyPersonality Psychology

Intelligence is a complex topic that psychologists have been studying for many years. Psychometric theories of intelligence attempt to measure and quantify intelligence scientifically. According to these theories of intelligence, intelligence is a person's ability to think abstractly, solve problems, and remember information. This ability is thought to be innate and heritable and can be measured through intelligence tests. Psychometric theories of intelligence have been influential in the development of intelligence tests and the study of intelligence. However, they have also been criticized for their lack of explanatory power and focus on school-related skills. So, in this article, we will discuss four such theories.

Unifactor Theory by Alfred Binet

It was proposed by Alfred Binet, and it is the oldest theory. Binet was one of the pioneers in this field who made effort to describe the idea of intelligence. He suggested that intelligence is composed of a single element that applies to all of a person's behavior. The hypothesis, which reduces all talents to a single capacity of general intelligence or "common sense," is the foundation upon which Alfred Binet founded his intelligence test. It suggests that all individuals are perfectly connected and would not consider individual differences in ability. It was criticized since other psychologists noted that many other factors contribute to intelligence.

Two-factors Theory by Charles Spearman

Two factors theory was developed in response to criticisms of previous theories. 1904, Charles Spearman proposed this viewpoint, as he was more interested in something common across many intellectual talents than in what made each one distinctive, just like someone studying the biology of mammals would research what made seemingly disparate species alike. He argued that individual talents do not reflect the essence of intelligence. He claimed that significant variances in people's mental test results are caused by a single intellectual aptitude, mental energy. He claimed that there were two components to intellectual capacity −

  • a general ability or common ability known as the "G" factor and
  • a collection of particular skills known as the "S" factor.

a collection of particular skills known as the "S" factor. General intelligence is a type of mental energy that runs across several activities. Specific abilities enable a person to deal with specific types of difficulties. For example, A's performance in music is attributable in part to general intelligence (g) and in part to specialized musical talent (s1). Similarly, A's achievement in mathematics is attributable in part to general intelligence (g) and in part to particular mathematical aptitude (s2). He may have other skills such as art (s3), language (s4), and so on. The total intelligence of A will be −

A =

This theory was also criticized as Spearman said that there are only two factors, but intelligence has more than two factors (s1, s2, s3, s4...). Additionally, the specific abilities possessed by some professions might overlap (like doctors and nurses). Hence, it gives birth to common factors.

Theory of Primary Mental Abilities (or Group Factor Theory)

The term group factor was suggested for the factors not common to all intellectual abilities, but common to certain activities comprising a group. LL Thurstone, an American psychologist, is prominent among the propagators of this theory. According to him, certain mental processes have a "primary" element that provides psychological and functional unity and distinguishes them from other mental operations. These mental operations are then grouped. Each of these primary factors is said to be largely self-contained. These fundamental components provide functional unity and coherence to the organization. Thurstone recognized nine such factors. However, it was criticized for failing to evaluate a general factor.

S. No. Factor Description
1.  Verbal factor (V) Concerns with comprehension of verbal relations, words, and ideas.
2.  Spatial Factor (S) Involved in the task in which the subject manipulates an object imaginatively in space.
3.  Numerical Factor (N) Ability to do numerical calculations rapidly and accurately.
4.  Memory Factor (M) Involves the ability to memorize quickly.
5.  Word Fluency Factor (W) Involved whenever the subject is asked to think of isolated words at a rapid rate.
6.  Inductive Reasoning Factor (RI) Ability to draw inferences on conclusions on the basis of specific instances.
7.  Deductive Reasoning Factor (RD) Ability to make generalized results.
8.  Perceptual Factor (P) Ability to perceive objects accurately.
9.  Problem-Solving Ability Factor (PS) Ability to solve problems with individual efforts.

Hierarchical Model of Intelligence

Arthur Jensen proposed hierarchical model. Jensen has suggested combining components of the multi-factor and G-factor theories to create a hierarchical framework. Such a hypothesis depicts intellect as being like a pyramid, which is conceptualized as two levels of abilities −

  • Level I or associative learning − it is characterized as the retention of input and the rote memorizing of elementary facts and abilities.
  • Level II, or conceptual learning − it is similar to the ability to alter and modify inputs or solve problems.

General intelligence (G), which may be seen in almost all types of intellectual work, is at the summit of the intelligence pyramid. Numerous specialized ability variables are placed below, such as Thurstone's core mental faculties. Similar to Spearman's (1927) S factors, there are more highly specialized talents at the base of the pyramid, which may be used for a single activity. This multilayered, hierarchical theory of intelligence draws inspiration from several component theories to create what may be the most logical conclusion of all these. Jensen felt that intelligence is inherited and that intelligence is more genetic than environmental. He also believed in intellectual variations among cultures. "Jensenism" refers to the idea of a genetic foundation for individual and ethnic variations in intellect and academic achievement.

Cattell's Fluid and Crystalised Intelligence

Cattell first distinguished fluid and crystallized intelligence as components of general intelligence. Fluid intelligence (Gf) is the capacity to reason, produce, transform, and manipulate many sorts of unique knowledge in real-time. All characteristics of fluid intelligence, including processing speed and efficiency, have been found to deteriorate roughly linearly with age beginning in early adulthood. Various cognitive capacities connected to fluid intelligence, such as memory, reasoning, and processing speed, diminish progressively across the adult life span. Fluid intelligence is a basic capacity related to genetic potentiality. Crystallized intelligence (Gc) is described as an experienced-based knowledge component of intelligence that is developed by engagement with one's surroundings. It is accumulating information gained by experience, culture, and past learning. Crystallized intellect is the consequence of life experiences and the effective processing and storage of knowledge gathered over a lifetime. This type of intelligence is frequently measured as knowledge and appears to be associated with education, physical health, and general cognitive competency. It is influenced by various factors, including motivation, opportunity, and culture. Thus, crystallized intelligence denotes the accumulation of practical experience and information earned over a lifetime of coping with various activities, events, and obstacles in everyday life.


Psychometric theories of intelligence suggest that intelligence is a measurable construct that can be assessed through standardized tests. These theories have been used to develop tests like the IQ test, which measures a person's intelligence quotient.

Updated on 13-Oct-2022 11:19:47