Final answer:
Alfred Binet and Theodore Simon developed the first intelligence test, the Binet-Simon Intelligence Scale, in 1905, which led to standardized psychometric testing and informed future intelligence tests, including those developed by David Wechsler.
Step-by-step explanation:
Alfred Binet and Theodore Simon's contribution to the history of psychometric testing originated in the early 20th century when they were commissioned by the French government to develop an intelligence test. In 1905, they created the Binet-Simon Intelligence Scale, the first intelligence test designed to identify children who would face difficulties in school. This test was groundbreaking because it provided a method to measure intellectual abilities, primarily through verbally based tasks. Considering the importance of their work, American researchers soon recognized the value of their contributions. Louis Terman, a professor at Stanford, later refined Binet's test by standardizing its administration and creating norms based on a wide cross-section of children's scores, leading to the development of the Stanford-Binet Intelligence Scale.
The innovations brought forward by Binet and Simon laid the groundwork for future intelligence tests, including the Wechsler scales developed by David Wechsler years later. Wechsler's contributions further expanded on Binet's work by incorporating both verbal and nonverbal subtests, reflecting a more comprehensive view of intelligence. These intelligence tests have stood the test of time and are still the foundation of contemporary psychometric testing practices.