8 to 12 Months
No doubt, by the second half of baby's first year, she will repeatedly drop things from her high chair -- a spoon, her bottle, or her sippy cup -- and squeal with delight when you fetch the objects...again and again.
What Babies Learn: This exasperating game actually helps reinforce the concepts of object permanence and cause and effect -- when your baby sends her sippy cup on a nosedive, it doesn't disappear but bounces and rolls across the kitchen floor. It also teaches her about gravity -- what goes up must come down -- and helps her realize that she can make an impact on her environment and get your attention. Bonus!
Game Plan: Save your sanity by giving your baby objects she can drop that won't make a mess, such as a rubber ball, plastic spoon, or paper cup. To add to the fun, be sure to say "Where did it go? There it is!" It can make mealtime a longer affair, but it will probably be less annoying now that you know your child's getting something out of it. If you're game, give her opportunities to drop things throughout the day, such as toy keys off the dining room table.