I have some of the spotteds, and they are... not bright. If there's a storm anywhere near coming in, they hide all day. Unless I put food in, then they gobble it up as fast as possible and then hide again. You'd think they'd eventually learn that the storm wasn't going to hurt them, especially since we get storms fairly often, but apparently they aren't capable of learning. They also seemingly haven't learned not to nibble on tankmates' flanks. Or bite each other. A couple of them have chomp marks out of their foreheads from when the males were sparring. Must not be much room in their heads for brain, I guess.
Ever see a school of silver dollars in the middle of a mad-dash panic suddenly realize there's food? They basically go "AAAAAAAAA OH WAIT FOOD *OMNOMNOM* AAAAAA *OMNOMNOM* AAAAA *OMNOM* AAAAAAAAAAAAAAA" until they're too tired and full to keep dashing.
Then again, a lot of schooling fish don't really seem to be very smart. I imagine they're mostly or entirely acting on instinct and merely reacting to stimuli rather than actually processing things and responding. Cichlids and solitary fish seem like they're thinking at least a little bit, and they usually seem to be actually watching things, but dollars kinda just act on their programming.