Charles Spearman and the Two-factor Theory of Intelligence

Psychology of Behaviour

• At the beginning of the 20th century, psychology was defined as the science of behaviour.
• John Watson popularized the term "behaviour".
• William McDougall developed the theory of instinct and social psychology in the English-speaking world.
• Walter Bowers Pillsbury's "Essentials of Psychology" (1911) defined psychology as the "study of behaviour".

Definitions of Psychology

• According to Robert Sessions Woodworth, "psychology lost its soul, then its mind, then its consciousness, but it still has behaviour of a sort".
• Burrhus Frederic Skinner defined psychology as "the science of behaviour and experience".

Theories of Intelligence

• Every measurement of intelligence is based on a theory, whether explicit or implicit.
• Theories of intelligence can be obvious or hidden.
• Examples of intelligence tests include the Wechsler Preschool and Primary Scale of Intelligence, the Stanford-Binet Intelligence Scale, and the Wechsler Intelligence Scale for Children.

Factor Analysis

• Charles Spearman invented factor analysis to identify the sources of individual differences underlying test scores.
• Spearman's Two-Factor Theory proposes that:
  • The first factor, g (general intelligence), is related to problem-solving.
  • The second factor, s (specific mental abilities), is related to verbal or math skills.

Criticisms of g Theory

• Theorists argue that a general factor is obtained in tests of intelligence because the tests are limited to academic and artificial tasks.
• The appearance of a general factor may be due to mathematical regularity rather than a real underlying factor.

The Theory of Primary Mental Abilities

• Louis Thurstone proposed a theory of primary mental abilities, which includes seven mental abilities.
• The seven primary mental abilities are:
  • Verbal Comprehension (involves understanding verbal material)
  • Verbal Fluency (rapidly producing words, sentences, and other verbal material)

Eastern and Western Conceptions of Intelligence

• Eastern conceptions of intelligence, such as Confucian and Taoist perspectives, emphasize benevolence, humility, and lifelong learning.
• Western conceptions of intelligence, on the other hand, emphasize academic achievement and enthusiasm for learning.
• Studies have found that Taiwanese Chinese conceptions of intelligence differ from Western conceptions, with factors such as interpersonal intelligence, intrapersonal intelligence, and intellectual self-effacement.