The ability to pretend is related to the ability to conceptualize the unseen. Scientists in fields like chemistry, astronomy, and biology use this skill to picture processes that are too remote or too small to observe readily. Children who do not have this skill will have problems visualizing chemical reactions, stars exploding, cells dividing, etc. Toys like building blocks, Legos, and dolls and action figures develop those skills. Encouraging children to build their own toys is even better.
Parents can encourage imaginitive play by engaging their children in games that require thinking.
Car rides are an excellent time for this. These games require thought, planning, and memory skills.