Sep 9, 2025·Taking an IQ Test

IQ Test Usage

Discover how IQ tests are used in education, employment, clinical, forensic, and research settings, offering insights into learning, work performance, and life outcomes.

Dr. Russell T. WarneChief Scientist

IQ tests are used in many different settings. Most commonly, though, they are used for:

Educational diagnosis, placement, and placement
Employment selection and promotion
Clinical and forensic settings
Research

Use of IQ in Schools and Education Settings

In schools and other educational settings, psychologists use IQ tests as part of a the processes of diagnosing a child with a learning disability or other condition. Usually the IQ test cannot -- by itself -- make a diagnosis. But it can be helpful in narrowing down the possible diagnoses or understanding the consequences of a disability. In school settings, IQ tests are also used to select children for different educational programs. Students who score well on the tests may be selected for gifted programs and advanced classes. This also occurs at the university level; even though colleges do not call them “IQ tests,” the SAT and ACT correlate strongly enough with IQ that their scores can be converted IQ.

Use of IQ in Employment Settings

Employers do not use IQ tests as much as schools do, but it still occurs. The largest employer in the United States to use an IQ test is the military, which uses the Armed Services Vocational Aptitude Battery (ASVAB). Although the military does not call it an “IQ test,” the ASVAB functions as an intelligence test and it is used to identify recruits who are smart enough for the many different jobs that the military needs to fill. Civilian employers sometimes use IQ tests also, usually for the purposes of hiring and promoting. Both the military and civilian employers use these tests because IQ is a good predictor of how quickly a person can be trained and how well they do their job after training.

Use of IQ in Clinical and Forensic Settings

In mental health settings, therapists, psychologists, and psychiatrists may use IQ tests for a variety of reasons. In addition to diagnosis, a mental health provider may administer an IQ test as part of a full psychological assessment to understand the full functioning and psychological profile of a new patient. Some therapists can also give an IQ test, such as the Reasoning and Intelligence Online Test (RIOT) for the insights it provides into a person’s cognitive functioning. This is sometimes important because sometimes the effectiveness of a therapy can sometimes vary by the client’s IQ level. In forensic settings (i.e., the court system, jails, and prisons), IQ tests are often part of a full psychological assessment that can help the authorities determine whether a person is fit to stand trial, whether they should be held in a mental facility or a prison, their suitability for parole, and even whether they qualify for execution.

IQ Tests in Research

Scientific researchers also use IQ tests in their work. Every year, hundreds of studies (perhaps thousands) that report IQ scores are published. Because of this massive amount of research, psychologists understand more about intelligence than almost any other individual trait. This research has shown that intelligence matters in many areas of life, including health and longevity, economic security, crime, and more.

IQ as a Predictor

IQ tests are used in all of these settings because IQ is a predictor of outcomes in almost every area of life. However, IQ is not always the best predictor, and it is not the only effective predictor. For example, in college admissions, IQ (in the form of SAT and ACT scores) is an excellent predictor of college academic performance, but the predictions are better when the test scores are combined with high school grades. This is because high school grades capture information that IQ does not (e.g., punctuality, the ability to set and complete long-term goals). This does not diminish the importance of IQ, but it does show the value of gaining a complete understanding of a person.