What Is the Normal Range for IQ?

An IQ score above 140 Indicates genius or nearly genius.

An IQ (intelligence quotient) test is a standardized method to know the mental ability of a person, usually against a peer group. IQ scores between 90 and 109 indicate normal or average intelligence. IQ remains a popular tool for job placement and educational services, particularly helping to place children in an appropriate setting for their educational needs.

• An IQ score is a numerical representation of an individual's intelligence within a normalized scale of test results.
• Most modern tests are adjusted so that the mean score is 100.
• IQ score is a combination or an average of multiple scores.

Questions on an intelligence test judge various categories such as working memory, verbal comprehension, processing speed, and perceptual reasoning. All these individual scores are combined to create your overall average IQ. Average IQ scores are often a combination of verbal and performance scales. Typically, individuals are stronger in one area than the other; therefore, the combination of these scores can better identify intelligence.

IQ tests generally focus on a person's:

• Memory
• Mathematical skills
• Reasoning ability
• Processing speed
• Language, including vocabulary
• Visuospatial processing (the ability to perceive, analyze, recall, and manipulate images oriented in space and keep track of the location of moving objects)

Scientists and psychologists started devising tests to assess intelligence in the late 1800s. In 1905, Alfred Binet, a French psychologist devised the first intelligence test. Soon after, William Stern, a German psychologist developed a more accurate method for estimating mental acuity, and coined the term "intelligence quotient." Research on IQ continues as more multifaceted tests are devised to include other skills such as social, emotional, and physical skills, and practical intelligence or what is known as "common sense."

An IQ test may be used for:

• Assessing a person's eligibility for a job
• Educational assessment
• Diagnosis of intellectual disabilities
• Psychological research purposes
• Evaluating a person's cognitive abilities, including attention, memory, mathematical skills, problem-solving skills, and response time

Several factors can influence a person's IQ, such as:

• Age - IQ increases with age and declines in old age
• Educational background
• Cultural practices and beliefs
• General health, including any underlying health conditions
• Environment
• Genetics
• Musical training
• Brain anatomy

To summarize, although IQ is commonly used to measure a person's intelligence, the concept of IQ has earned significant disrepute over the years.

• Researchers argue that IQ calculation may not be comprehensive enough to classify a person as more or less intelligent. There are various aspects to intelligence including spiritual, emotional, and creative aspects.
• People with a higher IQ do not necessarily perform well under different circumstances, including different levels of physical and mental stress, while some persons with normal IQ may excel under conditions of stress.
• Classifying people based on IQ can result in prejudice against people with a lower IQ. People have even made groups open for those with a certain level of IQ.

Your IQ score does not define you nor does it necessarily have a bearing on how successful your life is. IQ does not measure the abilities that are important for making good judgments in real-life situations. Hence, intelligence may span far beyond the confines of IQ, because a person's work productivity, ability to adapt to life situations, and emotional health cannot be predicted by their IQ score.

A score of 100 is said to be the average IQ and anything above that is above average intelligence for the person's age. IQ is based on a statistical calculation considering people who are expected to have a certain IQ. Hence, IQ scores are calculated for an individual in reference to an age-wise peer group. A person's IQ doesn't exist in isolation. The IQ score represents how a person's results compare to those of other people of their age.

What is an average IQ for my age?

As per research, the average IQ for each age group may be interpreted in the following manner.

IQ scores between 90 and 109 indicate a normal IQ range or average intelligence. Individual adults usually score somewhere between the 70-130 range, with 100 being the theoretical average. If you score above 130, then you have a score higher than the IQ ranges of the average population, and below 70 would be lower than the average population.

Superintelligent or gifted people get an average score of 120 to 140, and only about 2% of the population scores more than 130, considered to be genius. Many brilliant scientists, philosophers, poets, mathematicians, musicians, and chess players are known to have shot past an IQ score of even 200. Famous geniuses like Albert Einstein, Stephen Hawking, and Ada Lovelace were estimated to have an IQ of around 160.

Some of the highest IQ scores have been recorded in the range of 250 to 300, but many of these are disputed and controversial because of inconsistencies in the tests. Currently, Terence Tao, a Chinese-American mathematician is said to have the highest IQ in the world at 230. However, GIGA society, a group of people with average IQ scores above 190 recognized YoungHoon Kim of South Korea to have the all-time highest IQ in the world, with a score of 276.

An IQ score of 120 is definitely a good score since it means superior or above-average intelligence. Although not in the category of gifted or genius, an IQ score of 120 still falls within the top 10% of the population on the IQ scale.

The difference between aptitude tests and intelligence quotient (IQ) tests is as follows:

Aptitude tests

Most aptitude tests assess a specific set of skills; cognitive aptitude tests can measure a broad range of abilities and provide individual scores for each ability. Cognitive aptitude testing can be done through standardized tests or game-based assessments.

• These tests can measure specific areas of intelligence.
• Age is not a factor.
• There is a score for each category.
• These tests are highly predictive of job performance.
• The most common use is pre-employment testing.

IQ tests

They are typically standardized tests that cover a wide range of questions including logical, visual, spatial, classification, analogical, and pattern-driven questions. The IQ is determined by the deviation between the test score and the average test score of people of your age. IQ is considered a rough metric for general intelligence.

• These tests measure general intelligence.
• Age is used to determine IQ scores.
• One general score is determined.
• These are moderately predictive of job performance.
• The most common uses are research, education, and psychiatric assessment.

How does the average IQ of men and women compare?

Researchers in psychology and intelligence find that there is no difference in IQ between men and women. Historically, women were thought to have inferior intelligence than men because of their slightly smaller skull sizes. There is no scientific evidence that larger brains correspond to higher intelligence. Studies show that there is no difference in the average intelligence of girls and boys, however, slightly a higher number of girls than boys are around average scores, and a slightly larger number of boys score at the higher and lower extremes of IQ scores.

A recent study showed that men consistently overestimate their intelligence, while women underestimate theirs, likely because of the advantages and influence of the patriarchal cultures that have prevailed in most of the world. The average IQ in the world is approximately 100. According to the latest data from 2022, the average IQ is 98 in the U.S., with males averaging 99 and females averaging 97.

How often does the average IQ change over time?

The average IQ of an individual remains generally stable through life because IQ indicates the innate mental ability of a person. However, a person's knowledge and ability to more effectively utilize their intelligence can increase with age, typically from ages 20 to 50, after it which it starts declining. IQ itself is a relative measure in comparison with one's peer age group and doesn't usually change. The average IQ score is volatile during childhood and adolescence, although it is not clear why, but after that, it remains stable throughout life.

The average IQ of the population in general, however, has increased over time. This is known as the Flynn Effect, named after James Flynn who found evidence that the average IQ in the U.S. had increased by a mean IQ of 13.8 points in 46 years. This general increase in human intelligence is thought to be because of better education, better access to information, more exposure to complex tasks, and improved health and nutrition.

Is the average IQ different in various countries?

Yes, the average IQ does differ from country to country. Researchers at the Ulster Institute conducted a study in 2019, taking the data of average IQ scores by country, using standard IQ tests, and adding other measurements such as math, science, and reading assessments to evaluate the average IQ by country and globally. Typically, IQ scores are higher in countries that are more developed, with better education compared to poorer and less developed nations.

The study found that Japan had the highest average IQ with an IQ score of 106.48, followed closely by Taiwan at 106.47, and Singapore at 105.79. The U.S. ranked 31 with an average IQ score of 97. Singapore, Japan, and China, in that order, scored the highest in reading, math, and science tests.

Another important aspect of IQ by country is the “Intelligence Capital Index (ICI).” This is the ability of a country to capitalize on the knowledge level of the country, which is measured by assessing a country's environment for education, creativity, and ability to attract talent. A country with a lower average IQ score may score higher on ICI. For instance, the U.S. tops this list although it ranks 31st in average IQ, followed by the United Kingdom and Germany.

What IQ range indicates intellectual disability?

IQ ranges from 70 to 80 is considered borderline intellectual functioning and anything below 70 indicates intellectual disability. Following are the IQ classifications as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM), a reference book on mental health disorders published by the American Psychiatric Association (APA):

• IQ 71 to 84: Borderline intellectual functioning
• IQ 50-55 to approximately 70: Mild mental retardation
• IQ 35-40 to 50-55: Moderate retardation
• IQ 20-25 to 35-40: Severe mental retardation
• IQ below 20-25: Profound mental retardation

How can someone improve their IQ to move to a higher range?

While intelligence itself is an innate capacity, one can improve their IQ scores with learning and knowledge and working on improving their IQ test performances. Motivation and hard work can help one learn to better use their intelligence. An IQ test basically tests your knowledge and your mental agility in retrieving and applying your knowledge to deal with a situation.

Some ways to improve your average IQ scores and move to a higher range include:

• Learning new skills, such as learning music or a sport
• Regularly playing word and other puzzles and brain games
• Reading more and acquiring knowledge
• Learning a new language
• Training to improve verbal skills
• Maintaining good health with nutritious food, regular exercise, and adequate sleep