Which of the following Psychologists defined General Intelligence as 'a global…

Correct answer: David Wechsler (David Wechsler).

Explanation: David Wechsler defined intelligence as "a global capacity to think rationally, act purposefully and deal effectively with the environment." He emphasized a broad, practical view of intelligence and developed the Wechsler scales (for adults and children) to measure both verbal and performance abilities.

• Spearman: Proposed a single general factor ('g') based on common variance across tests; his view differs from the practical, global-capacity wording used by Wechsler.

• Thurstone: Argued for several primary mental abilities (multiple factors), not one global capacity as in the quoted definition.

• Thomson: Offered alternative explanations (such as a sampling theory) and critiqued the interpretation of a single factor; he did not present the quoted definition.

• Wechsler: The quoted phrase matches his emphasis on rational thinking, purposeful action, and effective adaptation to the environment.

Quick tip: Match key words in the stem (for example, "global capacity", "act purposefully", "deal effectively") to each psychologist's known definition or model to choose correctly.