Authors:

It is hard to get animals which normally pay little attention to each other to do things together. One can teach dolphins to jump simultaneously out of the water precisely because they show similar behavior spontaneously, but try to make two domestic cats jump together and you will fail.

"Elephants Trump Magic Goldfish" by Frans de Waal, www.huffingtonpost.com. March 8, 2011.
It is hard to get animals which normally pay little attention to each other to do things together. One can teach dolphins to jump simultaneously out of the water precisely because they show similar behavior