What this test measures
This is a browser version of a working memory task used at the Primate Research Institute in Kyoto, where young chimpanzees were shown numerals briefly and then had to touch them in order after the numerals were masked. The chimps, particularly a young male named Ayumu, performed strikingly well at very short exposure times, in some conditions outperforming the human participants.
The test starts at four numbers and adds one each time you clear a round. Your first click hides every remaining numeral, so the exposure period is however long you choose to look before starting. Three mistakes at the same level ends the run.
Average scores
| Numbers held | Standing |
|---|---|
| 4 – 5 | Getting started |
| 6 – 8 | Below to approaching average |
| 9 – 10 | Around average |
| 11 – 13 | Good |
| 14 – 16 | Very good |
| 17+ | Exceptional |
| Condition | Finding |
|---|---|
| 650ms exposure | Humans and chimps comparable |
| 210ms exposure | Young chimps ahead of humans |
| Numerals 1 – 9 | Standard task set |
| Age effect | Young chimps outperformed adults |
How to improve your score
- Take your time before the first click. Nothing hides until you click the number one. That period is unlimited, and using it properly is worth more than any other technique here.
- Memorise positions as a route, not a set. Tracing the path from 1 to 2 to 3 as a continuous movement is far easier to reproduce than recalling nine independent coordinates.
- Group the numbers into halves. Lock in the first four or five positions firmly, then the rest. Trying to hold all twelve at equal strength usually loses several of them.
- Use the screen edges as anchors. Absolute positions are hard. Relative ones, like near the top left corner or just right of centre, survive much better.
- Move fast once you start. The trace decays from the moment the numerals hide. Hesitating over the fourth position tends to cost you the sixth and seventh as well.
Frequently asked questions
What is a good chimp test score?
Around 9 is average. Reaching 12 is good, and anything above 15 is unusual. For reference, the chimpanzees in the Kyoto study worked reliably with nine numerals at exposure times far shorter than a human typically needs.
Can chimps really beat humans at this?
At very short exposure times, the young chimps in that study did outperform the human participants. The result is real but narrower than it is often reported: it applies to a specific task, a specific exposure window, and heavily trained animals.
Why do the numbers hide when I click the first one?
That is the task. The measurement is what you retained after the display was masked, so hiding on the first click is what makes it a memory test rather than a reading test.
How do people reach 15 or more?
By encoding the layout as a path and rehearsing it before starting, rather than by holding fifteen separate positions. It is a strategy result more than a capacity result.
Is this an intelligence test?
No. It measures one narrow component of working memory. Performance improves with practice and strategy, which is not what an intelligence measure is supposed to do.