In intelligence studies, Lewis Terman (1877-1956) was an American psychologist noted for his 1916 invention of the concept of the intelligent quotient "IQ" and the "IQ scale", a 1-200 point numerical scale (20 being idiot, 100 being average intelligence, 140 being genius level, and 200 being ceiling genius range) for intelligence ranking, testing, and classifications methodology.

See also
● Terman IQ

References
1. Terman, Lewis. (1916). The Measurement of Intelligence: an Explanation of and a Complete Guide for he Use of the Stanford Guide for the Use of the Stanford Revision and Extension of the Binet-Simon Intelligence Scale (I.Q., pg. 53, etc.). Houghton Mifflin Co.

Further reading
● Terman, Lewis. (1917). “The Intelligence Quotient of Francis Galton in Childhood,” American Journal of Psychology, 28: 209-15.

External links
● Lewis Terman – Wikipedia.
● Lewis Terman – Human Intelligence, University of Indiana.