An average IQ score is between 85 and 115. 68% of IQ scores fall within one standard deviation of the mean. That means that the majority of people have an IQ score between 85 and 115.
A Breakdown of IQ Scores
The average score on an IQ test is 100. These labels are often given for IQ scores:
- 1 to 24: Profound mental disability
- 25 to 39: Severe mental disability
- 40 to 54: Moderate mental disability
- 55 to 69: Mild mental disability
- 70 to 84: Borderline mental disability
- 85 to 114: Average intelligence
- 115 to 129: Above average or bright
- 130 to 144: Moderately gifted
- 145 to 159: Highly gifted
- 160 to 179: Exceptionally gifted
- 180 and up: Profoundly gifted
Understanding IQ Scores
IQ scores follow what is known as the bell curve. To understand what the score on an IQ test means, there are a few key terms that you should know.
Bell Curve: When IQ scores are plotted on a graph, they typically follow a bell-shaped curve.1 The peak of the “bell” occurs where the majority of the scores lie. The bell then slopes down to each side; one side represents lower than average scores and the other side represents scores that are above the average.
Mean: The mean is the average score. The average is calculated by adding all of the scores together, then dividing by the total number of scores.
Standard Deviation: This is a measure of variability in a population. A low standard deviation means that most of the data points are very close to the same value. A high standard deviation indicates that the data points tend to be very spread out from the average. In IQ testing, the standard deviation is plus or minus 15.1
What IQ Scores Really Mean
What exactly constitutes a genius score on a measure of intelligence? To understand the score, it is important first to learn a little more about IQ testing in general.
Today’s intelligence tests are based largely on the original test devised in the early 1900s by French psychologist Alfred Binet. To identify students in need of extra assistance in school, the French government asked Binet to devise a test that could be used to discover which students were most in need of academic help.
Based on his research, Binet developed the concept of mental age.2 Children of certain age groups quickly answered certain questions. Some children were able to respond to the questions typically answered by children of an older age, so these children had a higher mental age than their actual chronological age. Binet’s measure of intelligence was based on the average abilities of children of a particular age group.
Intelligence tests are designed to measure a person’s problem-solving and reasoning abilities.1 Your IQ score is a measure of fluid and crystallized intelligence. Your score on an IQ test indicates how well you did on these tests of mental abilities compared to other people in your age group
IQ Scores Are Increasing
IQ scores have also increased with passing generations.4 This is known as the Flynn effect, named for researcher James R. Flynn.
Since the 1930s when standardized tests first became widespread, researchers have noted a sustained and significant increase in test scores among people all over the world. Flynn has suggested that this increase is due to improvements in our abilities to solve problems, think abstractly, and utilize logic.
In a 2013 TED Talk, Flynn explained that past generations largely had to deal with the concrete and specific problems of their immediate environments.5
In contrast, people today are expected to think more about abstract and hypothetical situations. Not only that, but approaches to education have changed dramatically over the past 75 years and more people tend to have jobs identified as cognitively demanding.