The average IQ of a teenager is 100. IQ tests take age into consideration, so the average score is always 100, regardless of a person's age.
IQ tests are designed to test a person's ability to resolve problems and understand concepts. A well-written IQ test should test not a person's knowledge but their ability to learn. The main goals of an IQ test are to measure a person's spatial ability, mathematical ability, language ability and memory ability.
A person with an IQ between 90 and 110 is considered to have average intelligence. A score over 130 indicates an outstanding level of intelligence, while a score below 70 indicates potential mental retardation.