Step 1: Understanding the Concept:
The question asks to identify the pioneer of modern intelligence testing, specifically the psychologist credited with creating the first practical and systematic intelligence test.
Step 2: Detailed Explanation:
In 1905, French psychologist Alfred Binet, along with his collaborator Théodore Simon, developed the Binet-Simon Scale. This was commissioned by the French Ministry of Education to identify children who required special schooling.
This scale was revolutionary because it was the first to use a series of age-graded tasks to measure cognitive abilities like judgment, reasoning, and problem-solving. It introduced the concept of "mental age," which could be compared to a child's "chronological age."
While Théodore Simon (D) was a vital partner, Alfred Binet is universally recognized as the leader of the project and the principal founder of intelligence testing.
James McKeen Cattell (A) coined the term "mental tests" earlier, but his tests focused more on sensory and motor functions. David Wechsler (C) developed his influential intelligence scales (WAIS, WISC) much later, building on the foundation Binet had laid.
Step 3: Final Answer:
Alfred Binet is credited as the first psychologist to develop and start the systematic testing of intelligence with the creation of the Binet-Simon Scale.