How the chimp test works
Press Start test and 4 numbers, 1 to 4, appear at random spots in the grid. Look as long as you like. When you are ready, tap 1. At that moment all the other numbers turn into identical blank tiles, and you have to tap them in order, 2, 3, 4, from memory. It is a close cousin of the number memory test, except that here you remember positions instead of digits.
- Clear a round and the next one has one more number: 5, then 6, and so on.
- Tap a wrong tile and you get a strike. The page shows where the remaining numbers were, then deals a new layout with the same count.
- After 3 strikes the test ends. Your score is the highest count you cleared.
Tapping any number other than 1 before the round starts does nothing, so you cannot lose a strike by accident while looking. The grid has 8×5 spots on wider screens and 6×6 on narrow screens such as phones. Your best score and recent results are saved in this browser only.
Ayumu, the chimpanzee behind the test
The test is named after a famous experiment at the Primate Research Institute of Kyoto University. Sana Inoue and Tetsuro Matsuzawa trained three young chimpanzees, including one called Ayumu, and their mothers on a touchscreen task with the numerals 1 to 9. The design was the same as here: the numerals appeared at random positions, and as soon as the first one was touched, the others were replaced by white squares. The chimpanzees then touched the squares in ascending order.
The headline result came from a harder version. The numerals were shown for only a fraction of a second, 650, 430 or 210 milliseconds, before being masked. University students who did the same task became less accurate as the display time got shorter. Ayumu's accuracy stayed roughly the same, and at the shortest time he outperformed the humans. The study was published in Current Biology in 2007 and was widely reported as proof that a chimpanzee can beat people at a memory test.
The story has a second chapter. Later studies with human participants who practised the task, by Silberberg and Kearns (2009) and by Cook and Wilson (2010), reported that, with training, people can match or even beat Ayumu's performance. Ayumu himself had a lot of practice before the famous test. So the result is now read less as "chimpanzees have better memory" and more as a striking example of how fast and precise visual memory can become with practice. The debate is still discussed in comparative psychology.
How this version differs from the experiment
This page reproduces the untimed version: the numbers stay visible until you tap 1, so there is no fraction-of-a-second flash. That makes it a test of how many positions you can hold and replay in order, rather than of how much you can grab in a glance. Grabbing a pattern in one short look is closer to the visual memory test, where the squares stay lit for only 1 second. It also goes well beyond 9 numbers. Because the task and its scoring are not the same as in the study, there is no published typical score to compare with, and your result card shows your own history instead.
How to get further
- Read the path, not the numbers. Before tapping 1, trace the route from 1 to the last number with your eyes. A route is easier to keep than a set of separate points. The sequence memory test trains the same skill with a path that grows one step at a time.
- Group the numbers. Remember 1 to 4 as one shape, 5 to 8 as a second shape.
- Use the free time. There is no timer before you tap 1. Two or three slow looks at the layout pay off as the count grows.
- Keep the same device. The grid shape changes between narrow and wide screens, so compare scores on one screen.
- Rest. Fatigue hits this kind of task quickly.
Limits of an online test
This is a game for curiosity and practice, not a medical or psychological assessment and not an intelligence test. Your score depends on practice, attention and how the numbers happen to cluster, so judge yourself by your best of several rounds. If you notice real changes in your memory in daily life, talk to a doctor.
More memory games are on the memory and brain tests page.
Sources
- Inoue, S., & Matsuzawa, T. (2007). Working memory of numerals in chimpanzees. Current Biology, 17(23), R1004–R1005.
- Silberberg, A., & Kearns, D. (2009). Memory for the order of briefly presented numerals in humans as a function of practice. Animal Cognition, 12(2), 405–407.
- Cook, P., & Wilson, M. (2010). Do young chimpanzees have extraordinary working memory? Psychonomic Bulletin & Review, 17(4), 599–600.
Frequently asked questions
What is the chimp test?
A memory game based on a 2007 Kyoto University study in which a young chimpanzee called Ayumu memorized the positions of numbers on a touchscreen. You see numbers at random spots, tap 1, and then tap the hidden numbers in order from memory.
How is the chimp test scored?
You start with 4 numbers and each cleared round adds one. Your score is the highest count you cleared before your third strike.
Is there a time limit?
No. The numbers stay on screen until you tap 1, so you can study the layout as long as you like. After that you also have no timer, only your memory.
Did a chimpanzee really beat humans?
In the 2007 study Ayumu outperformed university students when the numbers were shown for only a fraction of a second. Later studies found that humans who practise the task can match or even beat his results, so the comparison is still debated.
Does this version flash the numbers like the study?
No. It reproduces the untimed version, where numbers stay visible until you tap 1. That is why your score here cannot be compared directly with the results in the paper.
How can I improve my chimp test score?
Trace the route from 1 to the last number with your eyes before tapping 1, group the numbers into small shapes, and use the free time to look twice. Play on the same device so the grid stays the same shape.