# Psychology of guessing number of objects

Someone I know is a pretty good guesser. One day we had a guessing contest, and went around the house guessing how many objects were in different containers.

I was surprised that I was outperformed every single time, and the other person guessed faster than I did every time as well. For example the person I was competing against guessed correctly, after taking less than five seconds to think, that a container had 218 marbles in it. This individual continued to perform consistently, test after test.

The person's accuracy rate over $$10$$ different tests was about $$95$$ percent, and $$98$$ percent for objects with over $$200$$ objects and less than $$300$$ objects.

What is the psychology of a person being able to accurately guess the number of objects in a container? Are there any neuro-correlates for this ability? Is there a certain time frame that one should guess in and not overthink too much?

I googled "the psychology of guessing objects" and didn't find anything useful. But I did find that as the number of objects increases, the accuracy tends to decrease linearly.

My own thoughts on the matter are:

1) It might have been a lucky day for the guesser.

2) They guessed with relatively few objects in the containers. If we had guessed with 500 or 1000 objects I think he or she would have seen a linear decrease in accuracy.