The Art of Sharing
The bottom line, say experts, is that kids won't start sharing unless they feel a need to do so. In other words, your preschooler may not want to have anyone else play with her beloved cash register, but when her pal refuses to let her have a turn riding his trike, she'll quickly appreciate the virtues of parting temporarily with her toys. (To reinforce the lesson, you could point out later how bad she felt when she wasn't allowed a turn.) But once a child starts, it's a skill she'll have for life: My boys actually pool their prized Pokémon cards now that they've figured out their collection is much more valuable when consolidated. Like my sons, most kids eventually learn that the personal and social payoffs are much more rewarding than the lonely advantage of keeping everything all for themselves.