And so I started talking to vets, animal researchers, zoo keepers. Most do not study animal intelligence, but they encounter it, and the lack of it, every day. The stories they tell us reveal what I'm convinced is a new window on animal intelligence: the kind of mental feats( 高超的思维技能 ) animals perform when dealing with captivity and the dominant species on the planet — humans. 3. The author is convinced that when dealing with human beings, animals are _________.