Exploring the Kaufman Kasanin Concept Formation Test for Cognitive Assessment

Most cognitive tests measure what you know – how many words you can recall, how many digits you can repeat. The Kaufman Kasanin Concept Formation Test does something different. It measures how you think: whether you can look at a set of objects, discover an underlying principle connecting them, and adapt your strategy when your first idea turns out to be wrong. That process – forming, testing, and revising abstract concepts – is one of the most distinctly human cognitive skills there is, and this test was specifically designed to put it under the microscope.

Origins and historical background 🔗

The test has roots in the work of Russian psychologist Lev Vygotsky (1896-1934), who developed a block-sorting technique with his colleague Leonid Sakharov to study how people form genuine abstract concepts rather than simply grouping objects by surface-level similarities. Vygotsky’s original version used 36 blocks; this was later streamlined to 22 by Boris Semeonoff in 1937.

Eugenia Hanfmann and Jacob Kasanin subsequently adapted Vygotsky’s method into a more structured clinical instrument, publishing their methodology in the Journal of Psychology in 1937. As documented in their foundational paper, the test emerged partly from Kasanin’s earlier work examining disordered conceptual thinking in patients with schizophrenia – making it one of the earliest psychodiagnostic tools developed with a clinical population in mind. The result is an instrument often called the Vygotsky Test or the Hanfmann-Kasanin Concept Formation Test, which remains in use today and is commercially available through specialized publishers like Stoelting Co.

What the test involves 🔗

The core task is deceptively simple: a person is presented with 22 wooden blocks that vary in color, shape, height, and width, and asked to sort them into groups. What makes the task cognitively demanding is that the correct groupings are not based on the obvious visible features – color and shape are irrelevant. The true organizing principle, written in nonsense words on the underside of each block, groups them by the combination of height (tall vs. short) and width (wide vs. narrow).

According to the Oxford Dictionary of Psychology, the blocks use four codes: one for tall and wide blocks, one for short and wide, one for tall and narrow, and one for short and narrow. The participant is not told what the codes mean – they have to figure it out through trial, feedback, and systematic reasoning.

After each sorting attempt, the examiner reveals whether a particular block has been placed correctly or not. This feedback is what drives the test forward. The individual must use that information to revise their hypothesis about the underlying rule, shift their approach, and try again. The test is untimed and individually administered, typically taking around 30 minutes.

What the test actually measures 🔗

Tests of conceptual thinking differ from most other psychological assessments in that they focus on the quality and process of thinking rather than the content of a response. Many have no single right or wrong answer per se – instead, scores reflect how abstract or concrete, complex or simple, flexible or rigid a person’s thinking is. The Kaufman Kasanin test fits squarely in this tradition.

At its core, the test evaluates whether a person can move from concrete, perceptually-driven sorting – grouping blocks by color because they look alike – toward genuine abstract categorization based on a multi-attribute rule. This mirrors what Vygotsky described as the shift from complex thinking (grouping by surface associations) to true conceptual thinking (grouping by an abstracted, internally consistent principle). As Vygotsky’s research demonstrated, this shift typically accelerates around age 12 and is not fully automatic even in adults – it requires deliberate cognitive effort.

Convergent thinking 🔗

One dimension the test measures is convergent thinking – the ability to zero in on a single correct solution. In the context of this test, convergent thinking is what allows a person to recognize that only one organizing principle (height × width) fits all the blocks correctly, and to commit to that solution. It reflects focused, analytical reasoning and the ability to eliminate incorrect hypotheses systematically. The relationship between convergent and divergent thinking has been extensively studied in cognitive psychology; convergent thinking is closely tied to structured, logical problem-solving.

Divergent thinking 🔗

Divergent thinking refers to the capacity to generate multiple possible solutions and explore different organizational frameworks. In the Kaufman Kasanin test, this shows up in the early phases of sorting, where the person must brainstorm possible rules – could it be shape? color? size alone? – before narrowing down to the correct one. The Modified Vygotsky Concept Formation Test, a later adaptation, formally separates the task into a convergent component and a divergent component, and introduces a shifting request that asks participants to find a new, alternative classification after identifying the first one. This addition makes the divergent component more explicit and measurable.

Error rates and strategy tracking 🔗

A key feature of the test is that it tracks not just whether someone arrives at the correct answer, but how many errors they make along the way and how efficiently they revise their approach after feedback. Research using a concept formation procedure based on the Hanfmann-Kasanin method has found that error rates typically decrease progressively across trials as the underlying concept is formed – errors are concentrated in the early stages, with subjects showing rapid improvement once the rule begins to click. A high and persistent error rate, or a failure to adjust after feedback, signals cognitive inflexibility rather than simple ignorance.

This is what makes the test diagnostically meaningful. Two people might both eventually find the correct sorting rule, but one might do so in three trials with minimal errors while another requires many trials and shows repeated adherence to the same failed strategy. That difference in rigidity versus flexibility of thinking is precisely what the test is designed to reveal. Research published in the Journal of Clinical Psychology in 1950 specifically examined the test as a measure of cognitive rigidity and its relationship to academic performance.

The cognitive demands: why this test is challenging 🔗

The test’s difficulty lies in the need to simultaneously hold multiple hypotheses in working memory, evaluate each one against incoming feedback, and discard approaches that are no longer viable. Abstract reasoning research in neuropsychology consistently highlights that this kind of higher-order processing is removed from direct sensory experience – it requires internal representation rather than just perception. Grouping blocks by color is perception. Grouping them by the intersection of two non-visible dimensions (height and width) is abstraction.

Vygotsky’s own theoretical work stressed that genuine concept formation requires more than identifying a shared trait – it demands that abstracted features be synthesized into a new, coherent organizing principle. A person who sorts blocks correctly because all the tall-wide ones happen to look similar has not necessarily formed an abstract concept; they may be responding to a perceptual cue. True mastery is demonstrated when the person can articulate the rule, apply it to new instances, and generate alternative classifications on request.

Clinical and research applications 🔗

The Kaufman Kasanin test has historically been most valuable in clinical and neuropsychological settings. Among its well-documented applications:

Schizophrenia and thought disorder – The test’s origins are directly tied to the study of disordered thinking. Kasanin and Hanfmann’s early work specifically examined concept formation in people with schizophrenia, finding characteristic impairments in the ability to form and sustain abstract groupings. Patients with significant cognitive disorganization tend to rely on concrete, surface-level sorting that they cannot generalize into a stable rule.

Autism spectrum disorder – A peer-reviewed study published in the journal Autism (2018) used the Vygotsky Blocks Test with adults with ASD and found they made significantly more errors than typically developing participants and required more examiner cues to identify the correct conceptual structure. Error rates correlated with performance IQ, and the pattern of difficulties mapped onto communication and creativity sub-scales, suggesting that the test captures specific higher cognitive processes relevant to the autism phenotype.

Intellectual disability and cognitive delays – The test is particularly well-suited for populations where verbal ability may not accurately reflect conceptual reasoning, since the task is performance-based rather than language-dependent. The modified version is especially useful in the assessment of intellectual disability and mental retardation, providing a structured record of how the person approaches and revises categorization tasks.

Neuropsychological assessment – Patients with frontal lobe damage or diffuse brain injury frequently show impaired performance on concept formation tasks. The pattern of errors – perseveration on a failed strategy, inability to shift after feedback – is diagnostically informative and maps onto known profiles of executive dysfunction.

How results are interpreted 🔗

Scoring the Kaufman Kasanin test is qualitative and process-focused. Examiners consider several dimensions: the number of trials needed to reach the correct solution, the total error rate, the nature of errors (random versus perseverative), the person’s verbal explanations of their sorting rationale, and whether they can generate alternative classifications when asked. A person demonstrating strong abstract thinking will show a systematic, hypothesis-driven approach – forming an initial guess, updating it efficiently with feedback, and clearly articulating the final rule.

In contrast, those with impaired abstract thinking may produce what Vygotsky called pseudoconcepts – groupings that superficially resemble correct categories but are driven by concrete associations rather than a true abstract principle. A pseudoconcept looks right on the surface but collapses when the person is asked to apply the rule to new items or explain the logic behind it. This distinction between genuine concept formation and pseudoconceptual thinking is one of the most clinically useful insights the test provides.

The test in the broader landscape of cognitive assessment 🔗

The Kaufman Kasanin test sits alongside other conceptual thinking tools – the Wisconsin Card Sorting Test, the Halstead Category Test, and the Twenty Questions Task – as part of a broader neuropsychological battery for assessing abstract reasoning. Each of these tests approaches concept formation from a slightly different angle; the Vygotsky-derived task is distinctive for its use of physical blocks, its reliance on non-verbal multi-attribute rules, and its emphasis on tracking the process of strategy revision rather than just the endpoint.

What sets the Kaufman Kasanin test apart from conventional intelligence measures is its focus on cognitive flexibility – the ability to abandon a wrong approach and construct a new one. Standard IQ tests tend to reward accumulated knowledge and quick retrieval. This test rewards something harder to measure: the willingness and capacity to revise your own mental model when the evidence requires it.

What do you think? Given that this test captures cognitive flexibility and the ability to revise abstract strategies – not just raw intelligence – do you think it might reveal aspects of thinking that standard IQ tests consistently miss? And how might the patterns of error it tracks look different across different age groups or neurological conditions?

References

1. https://americanhistory.si.edu/collections/object/nmah_694539
2. https://www.researchgate.net/publication/232555422_A_Method_for_the_Study_of_Concept_Formation
3. https://stoeltingco.com/Psychological-Testing/Kasanin-Hanfmann-ConceptModified-Vygotsky-Test~10113
4. https://www.oxfordreference.com/view/10.1093/oi/authority.20110803120305922
5. https://psylearners.psychotechservices.com/2016/08/ignou-corner-solved-assignments-mpce012_23.html
6. https://www.sciencedirect.com/topics/psychology/divergent-thinking-test
7. https://www.studocu.com/en-us/document/creighton-university/bachelor-of-arts-honours-course-psychology/3-concept-formation-full-experiment/92170401
8. https://onlinelibrary.wiley.com/doi/10.1002/1097-4679(195010)6:4%3C365::AID-JCLP2270060412%3E3.0.CO;2-H
9. https://link.springer.com/chapter/10.1007/978-1-4899-1950-2_15
10. https://pubmed.ncbi.nlm.nih.gov/28482683/