Five-year-old Brent loves to trick his baby sister Zoe by showing her a toy, then hiding it under a box. She thinks that it has ceased to exist, and he laughs. But one day Zoe knocks over the box and grabs the toy. Game over, Brent! Zoe has discovered .

object permanence

Explanation: peek-a-boo" or "hide and seek" is an example of object permanence.

It simply means that concrete objects are not "out of sight, out of mind", in other words things still continue to exist even when they are out of your sight.

A sign of object permanence is if they search for the object after it is moved or hidden.

answer; the cats meowing will temporarily increase, but then it will decrease;