Home/Historical IQ Tests/Wisconsin Card Sorting Test
1948 · GRANT & BERG · UNIVERSITY OF WISCONSIN · 8 SOURCES

Nobody tells you the rule. Then it changes.

You sort cards under four key cards and hear only "right" or "wrong". The rule is colour, shape or number, and in the original version it switched without warning.5,1 The test measures how quickly you let go of a rule that has stopped working.

▲
★★
✚✚✚
●●●●
The four key cards: one red triangle, two green stars, three yellow crosses, four blue circles6
PLAY · 64 CARDS · RULE SHIFTS AFTER 10 IN A ROW

Put the card under the key card it matches

Like the original, the screen won't say which rule is in force or when it changes. The rule shift after ten correct matches in a row follows common modern practice.8

Categories0/6
Correct0
Errors0
Perseverative0
CARD 1 / 64
●●●●
—The only feedback given

A demo based on the published design. It isn't the licensed test and isn't normed or diagnostic.

From the psychology of thinking to a monkey lab

Historians trace the idea to European research on thinking. The version used in clinics, though, was built by behaviourist experimenters.7

1900▲
Ach's sorting taskNarziss Ach had people sort cards of nonsense words by features of the objects the words stood for.2
1920★
Gelb and Goldstein's patientsKurt Goldstein used sorting tasks to test "concrete" versus "abstract" attitudes in people with brain damage.2
1940s✚
Harlow's primate labIn Wisconsin, rhesus monkeys adjusted when the rewarded stimulus changed, with the reward as their only clue. This suggested a way to measure reasoning and set-shifting in people.4
1948●
Berg's thesis, Grant and Berg's paperEsta Berg described a simple objective technique for measuring flexibility in thinking, thanking David Grant and Harry Harlow. A second paper with Grant already used the name "University of Wisconsin Card Sorting Test".1

Four colours, four shapes, one to four symbols

Each response card shows one to four copies of a single shape in a single colour. Crossing four colours, four shapes and four counts gives 64 combinations, the size of the classic deck.7 One card can match a key card on colour, shape or number, or on several at once, so a single sort doesn't show which rule the person is following.

COUNTSources disagree on the deck size. A study citing Grant and Berg gives 64 response cards, while another account of Berg's version gives 60.7,6
▲
▲▲
▲▲▲
▲▲▲▲
★★
★★★
★★★★
★
✚✚✚
✚✚✚✚
✚
✚✚
●●●●
●
●●
●●●
16 of the 64: every shape × colour, with the number varying

To warn or not to warn

BERG, 1948
colour ✓✓✓✗ ?…

The examiner changed the rule without warning. The only clue was that "right" suddenly became "wrong".1

NELSON, 1976
colour ✓✓✓"The rule has changed"

This version tells the person when the rule changes. That removes the surprise, but they still have to work out the new rule.1

A frontal-lobe test, and its doubters

1963
Milner's frontal-lobe studiesBrenda Milner, at the Montreal Neurological Institute, began using the test to assess prefrontal damage in patients with brain lesions. Her correction criteria are still part of standard scoring.2
1976
Nelson's modified versionA shorter version that announces each change of rule.1
1993
On a computerHeaton, Curtiss and Tuttle introduced a computerised version. The CANTAB set-shifting subtest is a common research alternative.1
2009
The specificity questionClinical studies found the traditional test doesn't distinguish frontal from non-frontal lesions, and brain imaging shows activity across many regions during the task.2

References

  1. [1]Eling, P., Derckx, K., & Maes, R. (2008). On the historical and conceptual background of the Wisconsin Card Sorting Test. Brain and Cognition, 67, 247–253. ScienceDirect.sciencedirect.com
  2. [2]Nyhus, E., & Barceló, F. (2009). The Wisconsin Card Sorting Test and the cognitive assessment of prefrontal executive functions: A critical update. Brain and Cognition. ScienceDirect.sciencedirect.com
  3. [3]Wisconsin Card Sorting inspired task (WCST). PsyToolkit experiment library.psytoolkit.org
  4. [4]Wisconsin Card Sorting Test (WCST): history, research & digital adaptations. Labvanced (2023).labvanced.com
  5. [5]Wikipedia contributors. Wisconsin Card Sorting Test (accessed 29 Sept 2026).en.wikipedia.org
  6. [6]Online vision- and action-based object classification using both symbolic and subsymbolic knowledge representations (2015). arXiv:1510.00604.arxiv.org/pdf/1510.00604
  7. [7]Eling, P. et al. (2008). On the historical and conceptual background of the Wisconsin Card Sorting Test (record with citing works). ResearchGate.researchgate.net
  8. [8]The effects of executive functions and social cognition on mental health — study protocol (NCT06213194). ClinicalTrials.gov (PDF).cdn.clinicaltrials.gov (PDF)
HOW TO CITE THIS PAGE
What's Your IQ. (2026). Wisconsin Card Sorting Test (1948). In Historical IQ Tests Archive. Retrieved September 29, 2026, from /en/historical-iq-tests/wisconsin-card-sort-1948
EDITORIAL RECORD
First published2026
Last reviewed29 September 2026
Sources8, all from visible search results
Open questions60 vs 64 cards; original rule-shift criterion
Canonical URLwhats-your-iq.com/en/historical-iq-tests/wisconsin-card-sort-1948

Related historical tests

Sibling test, a year earlier1947
Halstead-Reitan Neuropsychological Battery

Its Category Test also asks people to find an abstract principle from right/wrong feedback alone. The two are often grouped as the classic concept-formation tests of post-war neuropsychology.

ReferenceRead more →
Another executive classic1935
Stroop Color-Word Test

Name the ink colour, not the word. Like the WCST, it measures holding back a habitual response, and the two are now standard partners in executive-function assessment.

InteractiveTake it →
Clinical, brain-oriented1938
Bender Visual-Motor Gestalt Test

Copying nine geometric figures, used to screen for brain damage. It comes from the same gestalt-influenced clinical tradition that Goldstein's sorting work belongs to.

ReferenceRead more →
What IQ tests missed1939
Wechsler-Bellevue Intelligence Scale

The main adult IQ scale of the period. Card sorting became popular partly because people with frontal injuries could score normally on IQ tests yet fail to shift strategies.

ReferenceRead more →
Rules without words1936
Raven's Progressive Matrices

Like card sorting, matrices require finding an abstract rule from shapes, colours and counts. The difference is that a matrix item's rule never changes while you're working on it.

ReferenceRead more →
Same year, same idea1947
Raven's Coloured Progressive Matrices

Published a year earlier. It is another non-verbal test built on colour and pattern, aimed at children and older people, the same kind of test-takers for whom card sorting was later adapted.

ReferenceRead more →
Part of the Historical IQ Tests Archive. Editorial content under CC BY-SA 4.0. The card demo reproduces the published design; it is not the licensed WCST materials or scoring.

Flexible thinking is one part. See the rest.

Contemporary norms (mean 100, SD 15) and a four-domain breakdown, in about 30 minutes.

Take the modern IQ test →