The IQ scale
William Stern, German-Jewish psychologist who coined the 'intelligence quotient'; the modern tests were later devised by David Wechsler, a Romanian-born American Jew. (The first intelligence test itself was by the non-Jewish French psychologist Alfred Binet.)
1912 (term IQ); 1939 (Wechsler scales)
Germany; United States
In 1912 the German-Jewish psychologist William Stern introduced the 'intelligence quotient' (IQ), a way to express a score relative to age. The widely used modern IQ tests were later devised by David Wechsler, a Jewish immigrant to the United States. The first intelligence test itself had been created by the French psychologist Alfred Binet.
Part of “The Gifts of the Jews” — verified Jewish contributions to the world, with sources.