What does a 67 IQ mean?
A 67 IQ means a score higher than about 1.4% of people, roughly 1 in 72 at or below. It is in the extremely low range. Scores in the 60s and 70s also matter outside the clinic: in the United States they can decide whether a person facing the death penalty can be executed.
How far below average is 67?
An IQ of 67 is 33 points below the average of 100, or 2.2 standard deviations. About 1.4% of people of the same age score lower, the shaded sliver at the far left of the curve below.
On a test with a standard deviation of 16, such as older Stanford-Binet editions, the same result would be about 65, and on the Cattell scale, which uses 24, about 47. Why scales differ.
What an IQ of 67 tells you
In Atkins v. Virginia (2002), the US Supreme Court ruled that executing people with an intellectual disability violates the Eighth Amendment's ban on cruel and unusual punishment, and left it to the states to decide who qualifies. Because IQ scores are part of that decision, a few points either side of 70 have become some of the most closely argued numbers in American law.
The cases that followed show why a single test score can't carry that weight. Courts now hear evidence about measurement error, about which edition of a test was used and how old its norms were, and about the person's everyday functioning since childhood. That is the same full picture a psychologist would look for in any assessment.
How an IQ of 67 is classified
Different tests and manuals use different words for the same score, and the words have changed over time. Here is where 67 falls on each of the systems you are most likely to meet.
Sources: American Psychiatric Association, DSM-5 fact sheet on intellectual disability; World Health Organization, ICD-11, 6A00 disorders of intellectual development; Peltopuro, M. and others (2014), "Borderline intellectual functioning: a systematic literature review", Intellectual and Developmental Disabilities, 52(6), 419–443. WISC-V descriptors from Pearson's interpretive reports, as on our good IQ score guide.
Does 67 mean an intellectual disability?
A score of 67 on its own never makes a diagnosis. The American Psychiatric Association's DSM-5 describes intellectual disability as "approximately two standard deviations or more below the population, which equals an IQ score of about 70 or below", and requires three things together:
- Low intellectual functioning, confirmed by a clinical assessment and individually given, standardised testing.
- Difficulties with everyday adaptive skills in at least one of three domains: conceptual (language, reading, maths, memory), social (communication, judgement, friendships) and practical (personal care, money, work and school tasks).
- A start during the developmental period, in childhood or adolescence.
Severity is set by those everyday skills, not by the IQ number. That is why only about 1% of people have an intellectual disability (a 2011 meta-analysis of 52 population studies found about 10 per 1,000), even though about 2.3% score below 70 on the bell curve. Because tests have a margin of error, DSM-5 treats roughly 65 to 75 as the uncertain zone around 70.
Sources: American Psychiatric Association, DSM-5 fact sheet on intellectual disability; Maulik, P. K. and others (2011), "Prevalence of intellectual disability: a meta-analysis of population-based studies", Research in Developmental Disabilities, 32(2), 419–436; Hall v. Florida, 572 U.S. 701 (2014), which cites the DSM-5 range of 65 to 75.
Why scores near 70 matter in US courts
In Atkins v. Virginia (2002), the US Supreme Court ruled that executing a person with an intellectual disability is unconstitutional, and left states to decide who qualifies. In Hall v. Florida (2014) it struck down a rule that treated 70 as a strict cut-off, because every test has a margin of error. In Moore v. Texas (2017) it said courts must be guided by current medical standards rather than "lay stereotypes".
The practical lesson is the same outside a courtroom: a score of 67 is best read as a range, about 62 to 72, and judged alongside how a person actually manages daily life.
Sources: Atkins v. Virginia, 536 U.S. 304 (2002); Hall v. Florida, 572 U.S. 701 (2014); Moore v. Texas, 581 U.S. 1 (2017).
Is your 67 accurate?
Low scores are the most fragile results on any test, because almost everything that goes wrong on the day pulls a score down. Common reasons include:
- Running out of time. On timed tests, including ours, an unanswered question counts as wrong.
- Nerves. A review of 238 studies found test anxiety consistently linked with lower scores.
- Tiredness. Sleep loss hits attention and speed hardest, which costs points against the clock.
- Language and format. Taking a test in a second language, on a small screen or in an unfamiliar format can lower a result without saying anything about reasoning.
What a 67 means on our test
The Assessivo test moves in steps of about 2.5 points, so it can't give exactly 67: the nearest results are 65 (4 correct) and 68 (5 correct). Every question has four options, so someone guessing every answer at random averages nine correct, a score of 78. Random guessing falls this low about once in 29 attempts, so it can happen by bad luck, but it more often means many questions were skipped or rushed.
If any of this sounds like your session, retake the free IQ test when you are rested and have 25 quiet minutes. A score that moves a lot between attempts was never very solid.
Sources: von der Embse, N. and others (2018), "Test anxiety effects, predictors, and correlates: a 30-year meta-analytic review", Journal of Affective Disorders, 227, 483–493; Lim, J. and Dinges, D. F. (2010), "A meta-analysis of the impact of short-term sleep deprivation on cognitive variables", Psychological Bulletin, 136(3), 375–389. Guessing figures are worked out from the binomial distribution for 36 four-option questions.
What is the mental age for an IQ of 67?
The first IQ tests, for children, described performance as a "mental age": the age whose typical performance a child matched. IQ was mental age divided by real age, times 100. Run that old formula backwards and you get the figures below, for children only.
| Child's age | Performs like a typical child of about |
|---|---|
| 6 | 4 years |
| 8 | 5 years 4 months |
| 10 | 6 years 8 months |
| 12 | 8 years |
| 14 | 9 years 5 months |
For adults the idea doesn't work, which is why David Wechsler replaced it in 1939 with today's method: compare each person with others of the same age. An adult who scores 67 has an adult's knowledge, interests and experience. The score only says how their test performance compares with other adults'.
How common is an IQ of 67?
Line up 100 people of the same age and about 1 would score 67 or lower; the orange dot marks the place. In a city of a million, about 13,900 people would be at or below this level.
The bar shows the likely range on a professional test, about five points either way: 62 to 72, from the 0.56th to the 3rd percentile.
How 67 compares with nearby scores
| IQ | Percentile | Classic label | Score this low or lower |
|---|---|---|---|
| 57 | 0.21th | Extremely low | 1 in 482 |
| 62 | 0.56th | Extremely low | 1 in 177 |
| 67 | 1st | Extremely low | 1 in 72 |
| 72 | 3rd | Borderline | 1 in 32 |
| 77 | 6th | Borderline | 1 in 16 |
Questions about an IQ of 67
What percentile is an IQ of 67?
An IQ of 67 is at about the 1st percentile: it is higher than about 1.4% of people of the same age, and roughly 1 person in 72 scores this low or lower.
Is 67 a low IQ?
Yes. 67 is 33 points, or 2.2 standard deviations, below the average of 100. On the classic Wechsler labels it is extremely low. A single score is an estimate with a margin of error of about five points, so 67 is best read as roughly 62 to 72.
Does an IQ of 67 mean intellectual disability?
Not on its own. 67 is in the range where an intellectual disability (called a learning disability in the UK) is considered, but a diagnosis also needs significant difficulties with everyday skills that began during childhood, assessed by a qualified psychologist.
What is the mental age for an IQ of 67?
Mental age is an idea from the earliest tests for children. By the old formula, a 10-year-old scoring 67 would perform like a typical child of about 6 years 8 months. For adults it has no meaning: modern IQ tests compare adults with other adults, and an adult who scores 67 is not like a child.
What did Atkins v. Virginia decide?
In 2002 the US Supreme Court held that executing a person with an intellectual disability is unconstitutional under the Eighth Amendment. It left the states to set how intellectual disability is determined, which is why IQ scores near 70 often feature in these cases.
Related: the IQ range chart, what counts as an average IQ, what IQ measures and misses and how to tell if an online IQ test is accurate.
Behind a single score of 67 sit several separate abilities. Read about spatial reasoning, verbal reasoning, processing speed, fluid vs crystallized intelligence and abstract reasoning, or try the free pattern recognition test.
Information and support
If a professional assessment has given you, your child or someone you care for a score like 67, these organisations explain what it means in practice and what help is available.
Want a second reading?
Take the free Assessivo IQ test when you are rested and have 25 quiet minutes: 36 questions, and your estimated score and percentile as soon as you finish.
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