Fair Treatment and Ownership
What you will also find is that children this age have short memories. When your little girl snatches that red bucket back from her friend and shouts, "Mine!" she may really believe that the bucket belongs to her -- even if she's the one who stole it in the first place. However, when you talk about it with her, your child's budding sense of fair play might kick in and she'll agree to take turns with the bucket.
The flip side is that your child is much more acutely, noisily, and sometimes comically apt to declare that she's been shortchanged. Pour the same amount of juice into two different cups for a pair of kids this age, and you may have a mutiny on your hands as one cries, "But he got more!"
You can blame this partly on the fact that 4 ounces of juice in a short, wide glass looks like a lot less than the same amount in a tall, thin glass. But even if the cups were the same exact size and shape, but one was red and one was blue, your passionate 2-year-old might still make a fuss over not getting his "favorite" blue cup.
"Children this age have a true sense of who they are, and ownership and fair play become bigger issues," explains Leiderman. Your child won't really be ready to empathize enough with others to voluntarily take turns and play fair for many more months yet. Until then, you may have to resort to desperate measures -- like hiding that favored cup when your 2-year-old has a play date.