According to Charles Spearman's theory of intelligence, what is intelligence composed of in his well known two factor model?

Introduction / Context:
Charles Spearman was an early psychologist who made a major contribution to the study of intelligence by proposing the two factor theory. His work attempted to explain why people who perform well on one type of cognitive test often tend to perform well on others. This question asks what intelligence is composed of in Spearman theory, focusing on the components he labeled g and s.

Given Data / Assumptions:

• Spearman analyzed correlations between different mental ability tests.
• He noticed a positive correlation: people who scored high on one test often scored high on others.
• He concluded that there must be a general factor underlying performance across tasks.
• He also recognized that each specific test involves skills unique to that test.

Concept / Approach:
Spearman proposed that intelligence is composed of two types of factors. The first is a general factor, labeled g, which represents overall mental energy or general cognitive ability. This factor influences performance on many different cognitive tasks. The second set of factors are specific abilities, labeled s, which are unique to particular tests or skills, such as vocabulary, arithmetic, or spatial tasks. Together, g and s explain why people show both broad consistency and specific strengths and weaknesses in intellectual performance.

Step-by-Step Solution:
Step 1: Identify which option mentions both a general factor and specific factors. Step 2: Option a specifies a single general ability factor (g) plus a set of specific factors (s) for particular tasks, which matches Spearman two factor theory. Step 3: Option b describes several independent primary mental abilities with no general factor, which refers more to Thurstone perspective, not Spearman. Step 4: Option c refers to three types of intelligence (analytical, creative, practical), which is similar to Sternberg triarchic theory, not Spearman. Step 5: Option d describes multiple intelligences such as linguistic, logical, musical, and so on, associated with Gardner, not Spearman. Step 6: Option e focuses only on emotional intelligence, which is a later concept and not part of Spearman model. Step 7: Therefore, option a correctly summarizes Spearman view.

Verification / Alternative check:
Introductory psychology texts regularly describe Spearman as proposing one general intelligence factor, g, plus specific abilities, s, that account for performance on particular tests. Factor analysis of test scores shows a pattern consistent with a broad general factor underlying multiple abilities. Although later theorists challenged or expanded this view, the question only asks about Spearman own model, which is clearly the two factor theory.

Why Other Options Are Wrong:
Option b is closer to Thurstone primary mental abilities, which aimed to argue against a single g factor.
Option c corresponds to Sternberg triarchic theory of intelligence.
Option d describes Gardner multiple intelligences theory.
Option e focuses on emotional intelligence, which is not central to Spearman work and ignores cognitive abilities.

Common Pitfalls:
Students sometimes confuse different theorists theories because they all discuss types or components of intelligence. It is helpful to associate each name with a simple formula: Spearman is g plus s, Thurstone is several primary abilities, Gardner is multiple intelligences, and Sternberg is triarchic. Remembering these pairings helps avoid mixing up different models on exams.

Final Answer:
According to Spearman two factor theory, intelligence is composed of a single general ability factor (g) that influences all tasks and a set of specific factors (s) unique to particular tasks.