I read this on the John Byrne Forum and thought it was a pretty awesome story.
"On the National Geographic Channel t'other night I caught a few minutes of a program called "The Human Ape". Part of it was about experiments being done at the Max Planck Institute in Germany, testing the cognitive skills of other apes compared to humans.
The test shown was fairly simple. A clear plastic cylinder, about eighteen inches long, was attached to a table. Floating in about three inches of water in the bottom was a peanut. A four year old child was brought in, and told he could use anything in the room to get the peanut. On the table, about three feet away, was a beaker of water.
The kid tried to shove his hand down the tube, but found it too narrow. So he tried again. And again. And after several tries, lost interest.
Then a six year old boy was brought in, and he went thru the same routine, adding an attempt to rip the plastic tube off the table. No success, and he, too, lost interest.
Finally a 12 year old girl was brought in, and after a few moments she had a sudden inspiration (it was a real "lightbulb over the head" moment), took up the beaker of water and, pouring some into the tube, floated the peanut to the top.
Then they took to set-up to the orangutan cage at the zoo. No beaker this time, but there was a tap mounted on the wall, from which the orang routinely got her drinking water. The orang took one look at the tube, and almost immediately went to the tap, filled her mouth with water, and dribbled it into the tube. She repeated this until the peanut floated to the top."