Sapiens Test

2 min read

Ayumu the chimpanzee: does a chimp really have a better memory than you?

Five numbers appear on a screen in random spots. After 0.21 seconds they turn into white squares. Your job: touch the squares in order, from the smallest number to the largest. Ayumu the chimpanzee got it right in nearly 80% of trials. University students managed about 40%.

It’s one of my favorite studies, which is why I turned it into an experiment in the Lab. But before we announce that chimps have better memories than we do, it’s worth looking at what actually happened.

Who Ayumu is

Ayumu was born in 2000 at the Primate Research Institute of Kyoto University. His mother, Ai, had spent years there learning numerals and counting on a touchscreen. Ayumu grew up next to those screens and learned alongside her.

In 2007, Sana Inoue and Tetsuro Matsuzawa published the results of Ayumu and other chimpanzees at the institute in Current Biology. They compared them with university students doing the same task.

What they measured

The chimps and the students saw five numerals from 1 to 9. The numerals stayed on screen for a set time, then white squares covered them. You had to remember which numeral was where and touch the squares in the right order.

With longer viewing times, the students did fine. The difference showed up at the shortest one, 210 milliseconds. That’s not enough time to scan the numbers one by one. You have to take in the whole picture at once. Ayumu got it right in nearly 80% of trials, the students in about 40%.

What the study didn’t show

That chimps have a better memory than humans in general. It was about one very narrow thing: remembering where a few numbers were after seeing them for a split second.

What matters more is practice. Ayumu had been doing tasks like this since he was little and had a long training history behind him. The students had no such training. In 2009, Alan Silberberg and David Kearns checked what happens when people practice too. Human scores went up a lot. So at least part of Ayumu’s edge is training, not just the chimp brain.

That doesn’t make Ayumu any less impressive. Catching five numbers in 0.21 seconds is something most of us can’t do straight away. The comparison was just less even than the headlines made it sound.

Try it yourself

In the Lab you can do the same task: five numbers, 0.21 seconds, ten trials. At the end you see your score next to Ayumu’s and the students’. See where you land on your first try. If you want to see what practice does, come back in a few days and compare.

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