The Nature of Intelligence

The Nature of Intelligence: Introducing g and s

Overview of Intelligence

Charles Spearman's discoveries:

  • Found that schoolchildren's grades across different subjects were positively correlated.

  • Students typically scored similarly across academic subjects despite differences in subject matter.

  • These findings support the existence of a general cognitive ability, termed general intelligence or g.

Spearman's Factor Analysis

  • Factor analysis:

    • A statistical method used to assess the degree of relationships between variables to identify clusters, identified as "factors."

    • Inter-item correlations play a critical role in determining the degree of relatedness.

    • High correlation coefficients (close to 1.0) indicate items measure similar concepts.

    • Example of different factors:

    • Track and field tasks vs. swimming tasks showing lack of relatedness, indicating different factors of intelligence.

Cluster of Academic Grades

  • Spearman's conclusion:

    • Grades across subjects cluster because underlying the specific abilities required to learn a subject is a more general ability to learn: g.

    • g represents the overarching factor of intelligence, often called general intelligence or general cognitive abilities.

Levels of Intelligence According to Spearman

  • Two levels in intelligence:

    • Higher level (g):

    • A general ability applicable across varied context areas.

    • Lower level (s):

    • More specialized abilities related to specific subjects or tasks.

    • Example: Verbal intelligence assesses performance on verbal-based problems.

    • General intelligence (g) allows generalization across multiple contexts, while specialized forms of intelligence (s) are contextually sensitive.

Proposals of General Intelligence (g)

  • Spearman's hypotheses regarding general intelligence:

    1. Apprehension of one's own experience.

    2. The education of relations among experiences.

    3. The education of correlates (how experiences relate to one another).

Explanation of Apprehension

  • Apprehension means how one evaluates a situation:

    • Focus on certain elements while being less aware of background information.

    • Involves making implicit decisions about what information is important and how to formulate problems for resolution.

Mental Energy Metaphor

  • Second proposal regarding g:

    • General intelligence reflects the mental energy available throughout the brain's cortex.

    • The hypothesis suggests that individuals with higher intelligence can devote more mental energy to complex tasks, leading to better performance on difficult cognitive challenges.

Competing Theory by Louis Thurstone

  • Louis Thurstone's challenge to Spearman's theory of g:

    • Utilized factor analysis to identify multiple factors of intelligence.

    • Concluded that intelligence comprises seven primary mental abilities:

    1. Word fluency

    2. Verbal comprehension

    3. Numeric abilities

    4. Spatial visualization

    5. Memory

    6. Perceptual speed

    7. Reasoning

    • Refer to Table 10.2 for a comparative analysis of factor analysis vs. component analysis.