Irreversibility refers to the preoperational child's tendency to "believe that what has been done cannot be undone".
Irreversibility is a phase in early child advancement in which a kid erroneously trusts that activities can't be turned around or fixed. For instance, if a three-year-old kid sees somebody straighten a ball of play dough, he won't comprehend that the batter can without much of a stretch be changed into a ball. Kids regularly develop past this phase by age seven.
