Four, and then guessing
Up to about four objects people do not count at all — the number is simply there, instantly and with no effort. Psychologists call it subitizing. Above four the mechanism switches: either you count one by one, which the flash gives you no time for, or you estimate.
The estimate is not random. It is systematically fuzzy, and the fuzziness grows with the number: guessing 40 instead of 44 is normal, guessing 4 instead of 8 is not. That is the approximate number sense — old machinery, shared with infants and with animals.
Why the machine has no such line
- Counting objects in an image is a loop for a computer: the cost grows with the number of dots, but the answer stays exact.
- Human error grows in proportion to the quantity — roughly a fixed percentage, not a fixed number of items.
- This is one of the few tests here where the human answer is useful anyway: an estimate that is 10% off, arriving in 200 ms, is often worth more than an exact count that takes a minute.