What is the PTONI? The Primary Test of Nonverbal Intelligence explained
The PTONI test is a 5 to 15 minute nonverbal reasoning test for ages 3 to 9 from PRO-ED. See what its Nonverbal Index means and how it differs from IQ.
Dr. Russell T. WarneChief Scientist
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The PTONI test, or Primary Test of Nonverbal Intelligence, is an individually administered test of reasoning ability for children aged 3 years 0 months through 9 years 11 months, written by David J. Ehrler and Ronnie L. McGhee and published by PRO-ED in 2008. A psychologist, diagnostician, special educator, or speech-language pathologist gives it one-on-one in 5 to 15 minutes. The child looks at a page of pictures and points to the one that does not belong, so no speaking or writing is required. The PTONI is not a full IQ test. It produces one composite, the "Nonverbal Index," a standard score that estimates general reasoning ability from a single kind of nonverbal task, whereas a full-scale IQ from a comprehensive battery draws on many task types, including verbal, memory, and speed measures. This article explains what the PTONI measures, how the session runs, what the Nonverbal Index means, and where its limits lie.
What the PTONI measures
According to PRO-ED, the PTONI is "a theoretically sound, research-based method of assessing reasoning abilities in young children." The publisher describes it as a tool that psychologists, diagnosticians, special educators, speech-language pathologists, and other professionals can use to identify both severe intellectual deficits and superior cognitive intelligence. Whether a low or high score means anything clinically is a judgment for the qualified professional who gives the test and interprets it alongside other evidence.
Every item uses the same "odd one out" logic: the child sees a set of pictures in the Picture Book and points to the one that does not fit. PRO-ED explains that the items are arranged in order of difficulty, and that harder items call on a different kind of thinking.
• Early items: lower-order reasoning such as "visual perception" (noticing what is in a picture) and "spatial perception" (noticing where things are).
• Later items: higher-order reasoning, which the publisher lists as "analogical thinking" (seeing that one relationship is like another), "sequential reasoning" (working out what comes next in a series), and "categorical formulation" (grouping things by a shared rule).
The name says "nonverbal," and that word describes the format rather than a separate kind of intelligence. In a factor-analytic study of the PTONI's sibling test for older examinees, the Comprehensive Test of Nonverbal Intelligence, psychologist Ryan McGill wrote that "nonverbal" intelligence is not a viable entity in its own right, and that such tests more accurately measure general intelligence through nonverbal means. The same reading applies to a PTONI score: an estimate of general reasoning ability, collected without words.
Who gives the PTONI and how the session runs
The PTONI is a "Level C" instrument in PRO-ED's qualification system, the tier the publisher says requires "a high level of expertise in test interpretation," such as a doctorate with formal assessment training or a relevant state license. The complete kit contains an Examiner's Manual, a Picture Book with an easel back, and Examiner Record Forms.
PRO-ED lists the testing time as 5 to 15 minutes, short even among brief ability measures. Two design choices keep it that way.
• Minimal oral directions: the examiner says very little, and PRO-ED describes the result as "one of the simplest and easily understood of all nonverbal intelligence tests designed for young children."
• Pointing response: the child never has to speak, write, draw, or manipulate blocks, which the publisher says makes the format "especially appropriate for testing children who typically are not verbally or motorically well developed."
Directions are provided in eight alternative languages. A 2025 study in the journal Bilingualism: Language and Cognition, led by Kerry Danahy Ebert, reports following the PTONI manual's guidelines and using the test's instructions in English, Spanish, and Vietnamese, so that each child was tested in his or her preferred language. That is a real advantage for children from non-English-speaking homes, though the pictures themselves, and the objects and relationships they show, are still cultural content. For how far any test can travel across cultures, see our explainer on culture-fair intelligence tests.
PTONI scores and the Nonverbal Index explained
The PTONI reports three kinds of scores, described the same way by PRO-ED and by the distributor WPS.
• Nonverbal Index: a "standard score," the test's single composite. Standard scores on ability tests conventionally use a mean of 100 and a "standard deviation" (a measure of how spread out scores are) of 15, so a Nonverbal Index of 115 sits one standard deviation above the average same-age child.
• Percentile rank: the percentage of same-age children in the norm sample who scored at or below the child's raw score.
• Age equivalent: the age at which the child's raw score is typical. Most psychometricians treat age equivalents as a rough descriptor rather than a measurement.
The norms come from 1,010 children in 38 states, a sample PRO-ED describes as culturally and ethnically diverse and PAR reports as representative of United States census statistics. A published study of preschoolers with hearing loss, led by Krystal Werfel and reported in Ear and Hearing in 2020, cites the manual's internal-consistency reliability ("alpha," an index of how consistently the items measure the same thing) as .93. Using the usual formula for the "standard error of measurement" with that reliability and a standard deviation of 15 gives an error band of roughly 4 points, so a Nonverbal Index of 100 is best read as "probably somewhere in the mid-90s to mid-100s." That is a good result for a test this short, and typically a wider band than a comprehensive battery reports for its full-scale composite.
How the PTONI differs from a full-scale IQ test
The Nonverbal Index and a full-scale IQ sit on the same 100/15 scale and both estimate general intelligence. The difference is how much evidence sits behind each number.
• Breadth of content: a comprehensive battery such as the WPPSI, the Wechsler scale for ages 2:6 to 7:7, samples verbal comprehension, visual-spatial ability, fluid reasoning, working memory, and processing speed with separate subtests (five indexes from age 4), then combines them. The PTONI samples one task format. If a child's verbal reasoning and nonverbal reasoning differ, the PTONI cannot show it.
• Profile information: a full battery yields index scores that clinicians compare to one another. The PTONI yields one composite and no profile.
• Time and demands: the PTONI takes 5 to 15 minutes and asks only for pointing. A comprehensive preschool battery takes far longer and requires the child to understand and produce language on several subtests.
Those differences are why the PTONI exists. When a child cannot yet speak clearly, is deaf or hard of hearing, has a motor impairment, or is still learning English, a verbally loaded IQ battery can underestimate reasoning ability. A brief nonverbal measure avoids those confounds. For children aged 6 and up who need a longer nonverbal measure with subtest-level detail, PRO-ED publishes the CTONI-2, which covers ages 6 through 89.
How researchers and clinicians use the PTONI
Clinically, the PTONI usually appears as one piece of a larger evaluation. In research it plays two recurring roles.
• Screening for typical nonverbal ability: Ebert and colleagues used a PTONI standard score of 70 or above as an entry criterion for their study of bilingual children, so that low general ability could not explain the language results.
• A statistical control: a 2024 study in the Journal of Experimental Child Psychology led by Melissa Libertus had preschoolers complete the PTONI and entered the standard score into every analysis to control for nonverbal IQ while examining early number and geometry knowledge.
The Werfel study shows why the control matters. Among 92 children aged 3 to 6 who varied in hearing status, PTONI scores contributed unique variance to norm-referenced language test scores after maternal education and hearing status were controlled, and did not predict measures drawn from spontaneous speech. In plain terms, formal language tests partly reflect general reasoning ability, so a clinician who does not know a child's nonverbal ability can misread a language score.
Limitations and what the PTONI cannot tell you
A short, well-built test is still a short test. A few cautions apply.
• One task, one number: the odd-one-out format is a good proxy for general reasoning, yet it cannot separate the specific abilities a comprehensive battery measures, and the Nonverbal Index should never be relabelled a "full-scale IQ."
• Norms from 2008: the norm sample was collected for the 2008 publication. Norms age, and a standard score from older norms can drift upward relative to newer ones, a pattern known as the "Flynn effect."
• Young examinees: three- and four-year-olds vary from day to day in attention and cooperation, so a single low score at that age deserves retesting.
• Not a diagnosis: PRO-ED describes the PTONI as helping professionals identify intellectual deficits and superior ability. A diagnosis of intellectual disability, or a determination of giftedness, rests on a full evaluation by a qualified clinician using multiple sources of evidence.
For adults, a full-length test can be taken online. The RIOT IQ test, the Reasoning and Intelligence Online Test, was developed by RIOT IQ with psychometrician Dr. Russell T. Warne for people aged 18 and older. It contains 15 subtests across six cognitive indices (verbal reasoning, fluid reasoning, spatial ability, working memory, processing speed, and reaction time), takes about 52 minutes, and reports scores on the same mean-100, standard-deviation-15 scale used by the PTONI. Like the PTONI, it does not replace an individually administered diagnostic evaluation. You can take it at riotiq.com.
Frequently asked questions
What ages does the PTONI cover?
PRO-ED publishes the PTONI for children aged 3 years 0 months through 9 years 11 months. Its sibling test, the CTONI-2, picks up at age 6 and runs to 89.
Is the PTONI an IQ test?
Not in the full sense. It produces a single standard score, the Nonverbal Index, that estimates general reasoning ability from nonverbal picture items. A full-scale IQ from a comprehensive battery combines several kinds of tasks, including verbal ones.
What scores does the PTONI give?
A standard score called the Nonverbal Index, a percentile rank, and an age equivalent. Standard scores follow the usual convention of a mean of 100 and a standard deviation of 15.
Can the PTONI be given to a child who does not speak English?
Yes. Directions are provided in eight alternative languages, and published research reports using the Spanish and Vietnamese instructions. The pictures themselves are the same in every language.
Who can buy and administer the PTONI?
PRO-ED lists it as a Level C test, its highest qualification tier, which limits purchase to professionals with advanced assessment training or a relevant license, such as psychologists, diagnosticians, and speech-language pathologists.
References
1. PRO-ED. (2008). PTONI: Primary Test of Nonverbal Intelligence, Complete Kit [product page]. proedinc.com
2. PAR. (n.d.). Primary Test of Nonverbal Intelligence (PTONI) [product page]. parinc.com
3. Western Psychological Services. (n.d.). (PTONI) Primary Test of Nonverbal Intelligence [product page]. wpspublish.com
4. Werfel, K. L., Bassard, S. D., & Squires, C. (2020). Nonverbal intelligence predicts performance of preschool children with hearing loss on norm-referenced language measures but not language sample analysis. Ear and Hearing, 41(6), 1764–1771. pmc.ncbi.nlm.nih.gov
5. Ebert, K. D., Pham, G., Lee, H., & Dam, Q. (2025). Considering bias in language assessment with bilingual children. Bilingualism: Language and Cognition, 29(2), 432–442. doi.org
6. Libertus, M., Miller, P., Zippert, E. L., Bachman, H. J., & Votruba-Drzal, E. (2024). Predicting individual differences in preschoolers' numeracy and geometry knowledge: The role of understanding abstract relations between objects and quantities. Journal of Experimental Child Psychology, 247, 106035. doi.org
7. McGill, R. J. (2016). Investigating the factor structure of the Comprehensive Test of Nonverbal Intelligence-Second Edition (CTONI-2) using exploratory factor analysis. Journal of Psychoeducational Assessment, 34(4), 339–350. rjmcgill.com
Hero photo: Magnetic tangram pieces arranged on a board. Photo by Fumikas Sagisavas, via Wikimedia Commons, CC0 (cropped).
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