object permanence
Domestic dogs are very different from their wolf ancestors in their bodies and their behaviour. They're more docile for a start. But man's best friend has also evolved a curious sensitivity to our communication signals - a mental ability that sets them apart from wolves and that parallels the behaviour of human infants. Dogs and infants are even prone to making the same mistakes of perception.
Like infants less than a year old, dogs fail at a seemingly easy exercise called the "object permanence task". It goes like this: if you hide an object somewhere(say a ball under a cup) and let the…