Assessment of Stage 6 object permanence

The sensorimotor intelligence of cats and dogs was tested via successive invisible displacement object-permanence tasks. Preferred foods were used as baits, and a deception technique was used to control for odor cues. Dogs tested in their homes solved the problems consistently, but cats were seldom successful. It appears that dogs have fully developed sensorimotor intelligence, at least as indicated by object permanence. There is as yet no good evidence that cats have advanced beyond the fifth stage.