An individual of any age, including 13 years old, has an average IQ of 100. Normal IQ scores compare the performance of individuals within a given age group on a particular exam, and they vary from 85 to 115. After being normed, the test results are plotted on a bell curve.
IQ tests only examine the ability to analyse and solve problems; they do not measure creativity, practical intelligence, curiosity, or social aptitude. IQ labels are based on standard deviations from the mean of 100.
Scores between 115 and 130 are regarded as above ordinary, whereas those between 70 and 84 are regarded as having a borderline mental impairment. Gifted people score above 130, whereas mentally disabled people score below 70.