The average IQ of a 13-year-old, or person of any other age, is 100. Normal IQ scores range from 85 to 115, and scores compare the performance of people within a given age group on a specific test. The test results are then normed and placed on a bell curve.
IQ tests measure reasoning and problem-solving skills, but not creativity, practical intelligence, curiosity or social readiness. Labels based on IQ revolve around standard deviations from the normal 100. Scores from 115 to 130 are considered above average, while scores from 70 to 84 are considered borderline mental disability. Scores above 130 are gifted, while scores below 70 indicate mental disabilities.