Outsmarted by Ayumu: What a Chimpanzee Taught Us About Memory
Discover the famous Ayumu experiment, understand why chimps outperform humans at this task, and explore what this reveals about the evolution of memory.
In 2007, a young chimpanzee named Ayumu stunned the scientific world. At Kyoto University's Primate Research Institute, Ayumu demonstrated a remarkable ability to memorize the positions of numbers flashed briefly on a screen - outperforming adult humans consistently and dramatically.
This finding challenged assumptions about human cognitive superiority and opened new windows into the evolution of memory. The 'Chimp Test' based on this research has become a popular way to explore the limits of human spatial working memory.
The Ayumu Phenomenon: Primate Memory Research
Professor Tetsuro Matsuzawa and his team at Kyoto University trained chimpanzees to touch numbers 1-9 in ascending order on a touchscreen. The twist: after touching '1,' all other numbers were masked. The chimps had to remember where each number had appeared.
Ayumu excelled at this task, especially at high speeds. When numbers were shown for just 210 milliseconds - faster than a single eye fixation - Ayumu still performed accurately while human adults struggled significantly. This ability persists: Ayumu, now an adult, continues to outperform humans.
Researchers propose that chimpanzees may have retained an ancestral form of eidetic (photographic) memory that humans traded away during evolution. As human brains developed language capabilities, this immediate visual memory system may have been repurposed for linguistic processing.
Key Research Findings
- Young chimps consistently outperform adult humans at rapid spatial memory tasks
- The performance gap narrows with slower presentation speeds
- Human children (age 5-6) perform better than adults, similar to young chimps
- Training improves human performance but doesn't eliminate the gap with chimps
How the Chimp Test Works
Our chimp test replicates the core challenge of the Matsuzawa experiments. Numbers appear at random positions on a grid, and you must remember their locations after they disappear.
The test starts with just a few numbers and progressively increases difficulty. Unlike the original research, you get multiple attempts (lives) before the game ends.
How the Test Works
- 1Numbers (starting with 4) appear at random positions on the grid
- 2You click '1' and all numbers become hidden
- 3You must click the remaining positions in ascending order (2, 3, 4...)
- 4Correct completion advances you to the next level (one more number)
- 5Mistakes cost lives; the game ends when lives run out
Why Chimps Beat Humans (And What Affects Your Performance)
Understanding why chimps excel at this task illuminates the factors that affect human performance.
Eidetic Memory
Chimps appear to use a 'snapshot' memory that captures the entire display at once. Humans typically encode items sequentially.
Language Interference
Humans automatically try to verbalize numbers ('one, two, three...'), which slows encoding. Chimps don't have this linguistic overhead.
Processing Speed
The human advantage narrows at slower speeds, suggesting our sequential processing catches up given enough time.
Age
Human children perform better than adults at this task. Our eidetic-like abilities may diminish as language develops.
Practice
Humans can improve significantly with training, though chimps maintain their advantage at the highest speeds.
Attention and Focus
Full attention during the brief display period is critical. Any distraction drastically impairs performance.
Strategies to Improve at the Chimp Test
While you may never match Ayumu, these strategies can help you push closer to the limits of human spatial memory.
Gestalt Perception
Try to see the numbers as a pattern or shape rather than individual items. This mimics the holistic processing chimps use.
Minimize Verbalization
Resist the urge to 'read' the numbers. Focus on positions as visual-spatial information, not linguistic symbols.
Chunking by Position
Group numbers by spatial region (top-left cluster, bottom row). This reduces the number of items to track.
Eye Movement Strategy
Practice a consistent scan pattern. Some find it helpful to start from the lowest number and trace a path.
Relaxed Focus
Paradoxically, trying too hard impairs performance. A relaxed, receptive state allows faster visual encoding.
Speed Training
Practice at speeds faster than comfortable. This develops the rapid encoding that distinguishes high performers.
How You Compare: Population Statistics
Human performance on the chimp test varies widely. Here's how scores typically distribute (for reference, Ayumu can reliably complete level 9 at speeds where humans struggle with 5).
| Ranking | Score Range | Percentile |
|---|---|---|
| Chimp-Level Memory | 12+ numbers | Top 1% |
| Excellent | 9-11 numbers | Top 10% |
| Above Average | 7-8 numbers | Top 30% |
| Average | 5-6 numbers | Top 50% |
| Below Average | Under 5 numbers | Bottom 50% |
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Put your knowledge into practice with our Chimp Test test.
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