What does IQ stand for? IQ is short for intelligence quotient, a number that comes from a standardized test of skills such as reasoning, memory, vocabulary and pattern solving. The score compares one person's results with those of a large group of people the same age.
Most modern tests are built so that the average score is 100. People hear the letters in school testing, psychology classes, quiz shows and casual talk ("that took zero IQ points"), and the meaning shifts a little between a formal score and a loose way to say smart.
Quick facts
Stands for
Intelligence quotientType
Initialism, said I QAverage score
100 on most modern testsTypical range
About two thirds of people score between 85 and 115Given by
Trained psychologists and school specialistsRelated terms
EQ, mental age, aptitude test
What does IQ stand for, and why quotient?
The two words each have a clear meaning:
- I, intelligence: the general capacity to learn, think through problems and reason.
- Q, quotient: the answer you get when you divide one number by another.
Early in the 1900s, a German psychologist named William Stern proposed the quotient idea. A child's "mental age," based on test results, was divided by the child's actual age and multiplied by 100. A ten year old who tested like a typical twelve year old scored 120.
That method worked poorly for adults, since mental age stops rising in a neat line. Modern tests instead compare each person with others of the same age group. The word "quotient" stayed in the name even though no division is done anymore.
How IQ scores are spread out
Scores on most current tests follow a bell shaped curve, with most people near the middle.
| Score range | Where it sits |
|---|---|
| 85 to 115 | The average range, about two thirds of people |
| 115 to 130 | Above average |
| Above 130 | Well above average, about 2 percent of people |
| 70 to 85 | Below average |
Exact labels differ from one test to another, and a single score always comes with some room for error. Professionals usually report a range rather than one exact number.
Where you see IQ in real life
Schools may use IQ testing as one part of an evaluation for gifted programs or for special education services, often alongside grades, teacher reports and other tests. Psychologists use it when looking at learning differences or memory problems. In everyday speech, the letters mean little more than "brainpower."
A note home from school: "The evaluation will include a cognitive assessment (IQ) and a reading test." The school is asking permission to give a formal test of reasoning skills, scored by a trained specialist.
What an IQ score does not tell you
An IQ score measures certain thinking skills on a certain day. It does not measure creativity, effort, kindness, practical know how or how well a person handles feelings. Sleep, stress, language background and test anxiety can all move a score. Free quizzes online are not real IQ tests and their results should not be taken seriously.
How to say and write IQ
People say two letters, "I Q," so it falls in the initialism group described in what is an acronym. Keep both letters capitalized and leave out periods. It opens with the sound "eye," so the article is "an": "an IQ test." In sentences, both "an IQ of 105" and "an IQ score of 105" are standard.
IQ vs EQ and other look alikes
EQ usually means emotional quotient, a popular term for skill with emotions and relationships. It is a different idea and is not measured the same way. Students also meet GPA, grade point average, which reflects school grades rather than test reasoning, and the SAT, a college admission test. For more everyday letters like these, browse the famous acronyms list.
Questions people ask
What is a normal IQ score?
On most modern tests, 100 is the average, and scores from about 85 to 115 are in the average range. Roughly two of every three people fall there.
Can your IQ change?
Scores are fairly stable for adults but not fixed. Childhood scores can shift more, and health, schooling and test conditions all play a part.
Who invented the IQ test?
Alfred Binet, working in France in the early 1900s, built one of the first modern intelligence tests. The term intelligence quotient came from William Stern soon after.
Is IQ an acronym?
Not quite. Since you voice the I and the Q separately, the precise term is initialism. Most people simply call it an abbreviation or an acronym in everyday speech.
What does IQ stand for in texting?
It means the same thing, intelligence quotient, but usually loosely, as in "high IQ move" for a clever choice. It is not a real score in that use.