What the drift test measures
Numbered tiles drift across the board, bouncing off the edges. Click 1 and every numeral disappears, but the tiles carry on moving. You then have to click the rest in order while tracking where each one has gone. Clear a round and you get one more tile; three mistakes ends the run, and your score is the largest set you cleared.
This is the chimp test with the one thing that made it a memory task removed. In the standard version the tiles are still, so you can encode a fixed pattern: a shape, a path, a set of coordinates. Here that does not survive the first second, because everything you memorised has moved somewhere else.
What is left is closer to multiple object tracking, a well studied task where people follow several moving targets among identical distractors. Most adults can track around four objects reliably, and that limit is remarkably stubborn. The twist here is that you also have to keep their order, so it sits somewhere between tracking and working memory, and it is harder than either on its own.
What counts as a good round
| Cleared | Standing |
|---|---|
| 4 – 5 | Getting started |
| 6 – 7 | About average |
| 8 – 9 | Good |
| 10 – 12 | Very good |
| 13 – 15 | Exceptional |
| 16+ | Rare |
| Test | Typical | Why it differs |
|---|---|---|
| Chimp Test | 9 – 10 | Tiles stay put, so a pattern can be memorised |
| Drift Test | 6 – 7 | Tiles move, so only the objects can be tracked |
How to hold more of them
- Track objects, not positions. The instinct is to memorise where the numbers were. That information is worthless a second later. Pick the tiles out as things and follow them, the way you would keep an eye on a particular person in a crowd.
- Clear the ones near a wall first when you can. A tile about to bounce changes direction unpredictably from your point of view. Ones drifting through open space are easier to keep hold of, so deal with the awkward ones while you still have the numerals.
- Look at the middle, not at each tile. Tracking several moving objects works better with a soft gaze across the whole board than by darting between them. Chasing one at a time is how you lose the others.
- Group them into pairs. Two pairs are easier to hold than four separate things. Find tiles that happen to be moving together and treat them as one object until you need them.
- Do not rush the first click. The numbers stay visible until you click 1, and the tiles are already moving. Use that time to lock onto the later numbers, because that is the only look you get.
Frequently asked questions
How is this different from the chimp test?
The tiles never stop moving. In the standard chimp test they are static once hidden, so you can memorise a fixed pattern. Here everything drifts and bounces, so a remembered layout is useless within a second.
Why are my scores so much lower than on the chimp test?
Because it is a harder task. Most people clear around nine or ten still tiles but only six or seven moving ones. Tracking several moving objects has a firm limit of about four for most adults, and holding their order on top of that is harder still.
What is a good score?
Six or seven is about average. Eight or nine is good, and anything from ten upward is very good. Clearing sixteen is rare.
Do the tiles bounce off each other?
No, only off the walls. They pass through one another, which keeps it a tracking task rather than a physics puzzle.
Is this from a game?
Versions of this idea turn up as hacking and safe-cracking minigames in a lot of games. This is an independent browser version, not affiliated with any of them, and it is built on the same numeral task as the chimp test.
Does it measure anything real?
It measures multiple object tracking combined with order memory, both of which are studied perceptual abilities. It is not an intelligence test.