From the Wall Street Journal (paywall) about a recent psychological study by Gopnik et al, to be published in Psychological Science :
Suppose you see an experimenter put two orange blocks on a machine, and it lights up. She then puts a green one and a blue one on the same machine, but nothing happens.
Two red ones work, a black and white combination doesn’t. Now you have to make the machine light up yourself. You can choose two purple blocks or a yellow one and a brown one.
As a clever (or even not so clever) reader of this newspaper, you’d surely choose the two purple blocks.
But this simple problem actually requires some very abstract thinking. It’s not that any particular block makes the machine go. It’s the fact that the blocks are the same rather than different. Other animals have a very hard time understanding this. Chimpanzees can get hundreds of examples and still not get it, even with delicious bananas as a reward.
Still no signal from the mother ship? What gives?