What is the Number Memory Test?
The Number Memory Test (often called the Chimp Test) is an adaptive cognitive challenge designed to measure your working memory capacity. Unlike static quizzes, this test adjusts to your performance—adding digits when you succeed and removing them when you fail. You have 3 lives, and your goal is to recall the longest sequence of numbers possible.
How the Adaptive System Works
The game begins with 3 numbers. Take your time to memorize their positions (there is no time limit for the memorization phase). Once you tap the number '1', all other numbers disappear. You must then tap 2, 3, 4, etc., in the correct order from memory. This format, popularized by primate research, effectively tests your visuospatial short-term memory.
Pro Tips: How to Score Higher
- Don't Rush the Start: The timer only 'starts' mentally after you make your first tap. Spend time building a mental image of the grid before tapping '1'.
- Use "Chunking": Our brains struggle with long strings of data. Break the locations into small groups (e.g., a triangle of 3 numbers on the left, a line of 2 on the right).
- Trace a Narrative: Create a quick story or visual path connecting the numbers (e.g., "The 1 jumps to the 2, then slides down to 3").
- Stay Calm: Stress reduces working memory performance. Since you have 3 lives, play conservatively rather than speed-tapping.
The Science & Fun Facts Behind Memory
Why is this test so difficult? It's not just you—it's biology. Here are some scientifically backed facts about why humans and chimps perform differently on this task.
1. The "Magic Number 7" (Miller's Law)
If you find yourself stuck around level 7 or 8, you are experiencing Miller's Law. In 1956, Harvard psychologist George Miller published a famous paper titled "The Magical Number Seven, Plus or Minus Two." He argued that the average human brain can only hold about 7 items in its short-term memory at once. To get past this, you must use "chunking" (grouping numbers together) to hack your brain's limit.
2. Chimps Are Faster Than Your Eye
The inspiration for this test comes from Ayumu, a chimpanzee at Kyoto University. While humans struggle to memorize 9 numbers, Ayumu could recall their positions correctly after seeing them for just 0.21 seconds (210 milliseconds)—that's faster than the human eye can even move! Professor Tetsuro Matsuzawa's research suggests that while humans traded immediate memory for language capabilities, chimps retained this "eidetic imagery" (photographic memory) for survival.
3. Your "True" Limit Might Be Only 4
While Miller argued for 7 items, modern research suggests our focus is even narrower. A 2001 study by Nelson Cowan (University of Missouri) suggests the pure capacity of working memory—without mental tricks—is actually closer to 4 items. This explains why the game feels significantly harder as soon as you pass level 4 or 5.
Watch the original experiment that inspired this test:
Video: Chimpanzee Memory Test (Kyoto University)
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